The Indo-Greek Kingdom covered various parts of the northwest and northern Indian subcontinent from 180 BCE to around 10 CE, and was ruled by a succession of more than thirty Hellenic kings[1], often in conflict with each other. The kingdom was founded when the Greco-Bactrian king Demetrius invaded India in 180 BCE, ultimately creating an entity which seceded from the powerful Greco-Bactrian Kingdom centered in Bactria (today's northern Afghanistan). The city of Taxila in northern Pakistan would eventually serve as the Kingdom's cosmopolitan capital and seat of power.
During the two centuries of their rule, the Indo-Greek kings combined the Greek and Indian languages and symbols, as seen on their coins, and blended ancient Greek, Hindu and Buddhist religious practices, as seen in the archaeological remains of their cities and in the indications of their support of Buddhism. The Indo-Greek kings seem to have achieved a level of cultural syncretism with no equivalent in history, the consequences of which are still felt today, particularly through the diffusion and influence of Greco-Buddhist art.
The Indo-Greeks ultimately disappeared as a political entity around 10 CE following the invasions of the Indo-Scythian, Indo-Parthian and Kushans, although pockets of Greek populations probably remained for several centuries longer.
Greek presence in India
The Indian emperor Chandragupta, founder of the Mauryan dynasty, re-conquered around 322 BCE the northwest Indian territory that had been lost to Alexander the Great. However, contacts were kept with his Greek neighbours in the Seleucid Empire, Chandragupta received the daughter of the Seleucid king Seleucus I after a peace treaty, occupied northwestern territories as far as Arachosia, and several Greeks, such as the historian Megasthenes, resided at the Mauryan court:
"The Indians occupy [in part] some of the countries situated along the Indus, which formerly belonged to the Persians: Alexander deprived the Ariani of them, and established there settlements of his own. But Seleucus Nicator gave them to Sandrocottus in consequence of a marriage contract, and received in return five hundred elephants." Strabo 15.2.1(9) [2]
Bilingual edict (Greek and Aramaic) by king Ashoka, from Kandahar. Kabul Museum.Greek populations apparently remained in the northwest of the Indian subcontinent under Mauryan rule. Chandragupta's grandson Ashoka, who had converted to the Buddhist faith declared in the Edicts of Ashoka, set in stone, some of them written in Greek, that he converted to Buddhism Greek populations within his realm:
"Here in the king's domain among the Greeks, the Kambojas, the Nabhakas, the Nabhapamkits, the Bhojas, the Pitinikas, the Andhras and the Palidas, everywhere people are following Beloved-of-the-Gods' instructions in Dharma." Rock Edict Nb13 (S. Dhammika).
Finally, some of the emissaries of Ashoka, such as the famous Dharmaraksita, are described in Pali sources as leading Greek ("Yona") Buddhist monks, active in Buddhist proselytism (the Mahavamsa, XII[3])
The Greco-Bactrian kingdom
Alexander had established in Bactria several cities (Ai-Khanoum, Begram) and an administration that were to last more than two centuries under the Seleucids and the Greco-Bactrians, all the time in direct contact with Indian territory.
The Greco-Bactrians maintained a strong Hellenistic culture at the door of India during the rule of the Mauryan empire in India, as exemplified by the archaeological site of Ai-Khanoum. When the Mauryan empire was toppled by the Sungas around 180 BCE, the Greco-Bactrians expanded into India, where they established the Indo-Greek kingdom.
Early history
Local turmoil preceded the invasion of northern India undertaken by Demetrius, son of the Greco-Bactrian king Euthydemus, circa 180 BCE. General Pusyamitra Sunga had destroyed the ruling Mauryan King and had recently founded the Sunga dynasty (185–78 BCE). Written evidence of the initial Greek invasion survives in the Greek writings of Strabo and Justin, and in Sanskrit in the records of Patanjali, Kalidasa, and in the Yuga Purana, among others. Coins and architectural evidence also attest to the extent of the initial Greek campaign.
Evidence of the initial invasion
According to Strabo, Greek advances temporarily went as far as the Sunga capital Pataliputra (today Patna) in eastern India:
"Those who, after Alexander, advanced beyond the Hypanis, to the Ganges and Pataliputra." (Strabo, 15-1-27)
The 1st century BCE Greek historian Apollodorus, quoted by Strabo, affirms that the Bactrian Greeks, led by Demetrius I and Menander, conquered India and occupied a larger territory than the Macedonians under Alexander the Great, going beyond the Hypanis towards the Himalayas.
The Roman historian Justin also mentioned the Indo-Greek conquests, describing Demetrius as "King of the Indians" ("Regis Indorum"), and explaining that after vanquishing him Eucratides in turn "put India under his rule" ("Indiam in potestatem redegit"). Although "India" only meant the upper Indus for Alexander the Great, since the embassies of Megasthenes in the 3rd century BCE "India" meant to the Greeks most of the northern half of the Indian subcontinent, an area roughly corresponding to the extent of the Mauryan Empire at its largest. Greek and Indian sources tend to indicate that the Greeks ruled in Pataliputra until they were forced to retreat following the coup staged by Eucratides back in Bactria circa 170 BCE, suggesting an occupation period of about eight years.
To the south, the Greeks occupied the areas of the Sindh and Gujarat down to the region of Surat (Greek: Saraostus) near Mumbai (Bombay), including the strategic harbour of Barigaza (Bharuch), as attested by several writers (Strabo 11; Periplus of the Erythraean Sea, Chap. 41/47) and as evidenced by coins dating from the Indo-Greek ruler Apollodotus I:
"The Greeks... took possession, not only of Patalena, but also, on the rest of the coast, of what is called the kingdom of Saraostus and Sigerdis." (Strabo 11.11.1)
The 1st century CE Periplus of the Erythraean Sea describes numerous Greek buildings and fortifications in Barigaza, although mistakenly attributing them to Alexander, and the circulation of Indo-Greek coinage in the region:
"The metropolis of this country is Minnagara, from which much cotton cloth is brought down to Barygaza. In these places there remain even to the present time signs of the expedition of Alexander, such as ancient shrines, walls of forts and great wells." Periplus, Chap. 41
"To the present day ancient drachmae are current in Barygaza, coming from this country, bearing inscriptions in Greek letters, and the devices of those who reigned after Alexander, Apollodorus (sic) and Menander." Periplus Chap. 47
Indian sources
Various Indian records describe Greek (called Yavana) attacks on Mathura, Panchala, Saketa, and Pataliputra. Patanjali, a grammarian and commentator on Panini around 150 BCE, describes in the Mahabhasya, the invasion in two examples using the imperfect tense of Sanskrit, denoting a recent event:
"Arunad Yavanah Saketam" ("The Yavana [Greeks] were besieging Saketa")
"Arunad Yavano Madhyamikam" ("The Yavana were besieging Madhyamika (the "Middle country").
The Anushasanaparava of the Mahabharata affirms that the country of Mathura, the heartland of India, was under the joint control of the Yavanas and the Kambojas. Accounts of battles between the Greeks and the Sunga in Central India are also found in the Malavikagnimitra, a play by Kalidasa which describes a battle between Greek forces and Vasumitra, the grandson of Pushyamitra, during the latter's reign.
Also the Brahmanical text of the Yuga Purana, which describes Indian historical events in the form of a prophecy, relates the attack of the Indo-Greeks on the capital Pataliputra, a magnificent fortified city with 570 towers and 64 gates according to Megasthenes, and describes the ultimate destruction of the city's walls:
"Then, after having approached Saketa together with the Panchalas and the Mathuras, the Yavanas, valiant in battle, will reach Kusumadhvaja ("The town of the flower-standard", Pataliputra). Then, once Puspapura (another name of Pataliputra) has been reached and its celebrated mud[-walls] cast down, all the realm will be in disorder."
According to the Yuga Purana a situation of complete social disorder follows, in which the Yavanas rule and mingle with the people, and the position of the Brahmins and the Sudras is inverted:
"Sudras will also be utterers of bho (a form of address used towards an equal or inferior), and Brahmins will be utterers of arya (a form of address used towards a superior), and the elders, most fearful of dharma, will fearlessly exploit the people. And in the city the Yavanas, the princes, will make this people acquainted with them: but the Yavanas, infatuated by war, will not remain in Madhyadesa." (Yuga Purana, Paragraph 55-56, 2002 edition.)
Archeological remains
The city of Sirkap, today in northwestern Pakistan, was built according to the "Hippodamian" grid-plan characteristic of Greek cities, suggesting it may have been built by Demetrius. Numerous Hellenistic artifacts have been found, in particular coins of Greco-Bactrian kings and stone palettes representing Greek mythological scenes. Some of them are purely Hellenistic, others indicate an evolution of the Greco-Bactrian styles found at Ai-Khanoum towards more indianized styles. For example, accessories such as Indian ankle bracelets can be found on some representations of Greek mythological figures such as Artemis. Various Buddhist structures, such as the Butkara Stupa in the area of Swat were decorated with Hellenistic architectural elements from the 2nd century BCE.[15]
Ancient fortifications have been unearthed in Rajagriha, south of Pataliputra, which are similar in structure to the Indo-Greek fortifications of Sirkap and Barikot: stone walls connected by jutting rectangular towers, reinforced by a low structure to repel siege machinery, in contrast to the mud walls used throughout the country at that time
Retreat
The first invasion was completed by 175 BCE, as the Indo-Greeks contained the Sungas to the area eastward of Pataliputra, and established their rule on the new territory. Back in Bactria however, around 170 BCE, an usurper named Eucratides managed to topple the Euthydemid dynasty. He took for himself the title of king and started a civil war by invading the Indo-Greek territory, forcing the Indo-Greeks to retreat from their easternmost possessions and establish their new oriental frontier at Mathura, to confront this new threat:
"The Yavanas, infatuated by war, will not remain in Madhadesa (the Middle Country). There will be mutual agreement among them to leave, due to a terrible and very dreadful war having broken out in their own realm." (Yuga Purana, paragraphs 56-57, 2002 edition).
The Hathigumpha inscription, written by the king of Kalinga, Kharavela, also describes the presence of the Greek king "Demetrius" with his army in eastern India, apparently as far as the city of Rajagriha about 70 km southeast of Pataliputra and one of the foremost Buddhist sacred cities, but claims that Demetrius ultimately retreated to Mathura on hearing of Kharavela's military successes further south:
"Then in the eighth year, (Kharavela) with a large army having sacked Goradhagiri causes pressure on Rajagaha (Rajagriha). On account of the loud report of this act of valour, the Yavana (Greek) King Dimi[ta] retreated to Mathura having extricated his demoralized army and transport." Hathigumpha inscription, in Epigraphia Indica, Vol. XX.
In any case, Eucratides seems to have occupied territory as far as the Indus, between ca 170 BCE and 150 BCE. His advances were ultimately checked by the Indo-Greek king Menander I (Milinda), previously a general of Demetrius, who asserted himself in the Indian part of the empire, apparently conquered Bactria as indicated by his issue of coins in the Greco-Bactrian style, and even began the last expansions eastwards.
Consolidation and rise of Menander I
Menander (Milinda) is considered as probably the most successful Indo-Greek king, and the conqueror of the vastest territory.[18] The finds of his coins are the most numerous and the most widespread of all the Indo-Greek kings. In Antiquity, from at least the 1st century CE, the "Menander Mons", or "Mountains of Menander", came to designate the mountain chain at the extreme east of the Indian subcontinent, today's Naga hills and Arakan, as indicated in the Ptolemy world map of the 1st century CE geographer Ptolemy. Presumably the "Menander Mons" were so named because they marked the easternmost extent of his Indian conquests. Menander is also remembered in Buddhist literature (the Milinda Panha) as a convert to Buddhism: he became an arhat whose relics were enshrined in a manner reminiscent of the Buddha. He also introduced a new coin type, with Athena Alkidemos ("Protector of the people") on the reverse, which was adopted by most of his successors in the East.
Conquests east of the Punjab region were most likely made during the second half of the century by the king Menander I.
Following Menander's reign, about twenty Indo-Greek kings are known to have ruled in succession in the eastern parts of the Indo-Greek territory. Upon his death, Menander was succeeded by his queen Agathokleia, who for some time acted as regent to their son Strato I.
Culture
Buddhism flourished under the Indo-Greek kings, and it has been suggested, although direct evidence is lacking, that their invasion of India was intended to show their support for the Mauryan empire, which had a long history of marital alliances, treaties of friendship, and exchange of ambassadors and religious emissaries with the Greeks, and to protect the Buddhist faith from the religious persecutions of the Sungas. The city of Sirkap founded by Demetrius combines Greek and Indian influences without signs of segregation between the two cultures.
The first Greek coins to be minted in India, those of Menander I and Appolodotus I bear the mention "Saviour king" (BASILEOS SOTHROS), a title with high value in the Greek world which indicated an important deflective victory. For instance, Ptolemy I had been Soter (saviour) because he had helped save Rhodes from Demetrius the Besieger, and Antiochus I because he had saved Asia Minor from the Gauls.
Also, most of the coins of the Greek kings in India were bilingual, written in Greek on the front and in Pali (in the Kharoshthi script) on the back, a tremendous concession to another culture never before made in the Hellenic world. From the reign of Apollodotus II, around 80 BCE, Kharoshthi letters started to be used as mintmarks on coins in combination with Greek monograms and mintmarks, suggesting the participation of local technicians to the minting process. Incidentally, these bilingual coins of the Indo-Greeks were the key in the decipherment of the Kharoshthi script by James Prinsep (1799-1840). Kharoshthi became extinct around the 3rd century CE.
In Indian literature, the Indo-Greeks are described as Yavanas (transliteration of "Ionians"). Direct epigraphical evidence involves the Indo-Greek kings, such as the mention of the "Yavana king" Antialcidas on the Heliodorus pillar in Vidisha, or the mention of Menander I in the Buddhist text of the Milinda Panha. In the Harivamsa the "Yavana" Indo-Greeks are qualified, together with the Sakas, Kambojas, Pahlavas and Paradas as Kshatriya-pungava i.e foremost among the Warrior caste, or Kshatriyas. The Majjhima Nikaya explains that in the lands of the Yavanas and Kambojas, in contrast with the numerous Indian castes, there were only two classes of people, Aryas and Dasas (masters and slaves). The Arya could become Dasa and vice versa.
Religion
In addition to the worship of the Classical pantheon of the Greek deities found on their coins (Zeus, Herakles, Athena, Apollo...), the Indo-Greeks were involved with local faiths, particularly with Buddhism, but also with Hinduism and Zoroastrianism.
Buddhism
The Edicts of Ashoka, inscribed during the reign of the Indian emperor Ashoka (273-232 BCE), claim that the Greek populations of the northwestern Indian subcontinent (in today's Afghanistan and ancient Gandhara) had already welcomed Buddhism by around 250 BCE:
"Here in the king's domain among the Greeks, the Kambojas, the Nabhakas, the Nabhapamkits, the Bhojas, the Pitinikas, the Andhras and the Palidas, everywhere people are following Beloved-of-the-Gods' instructions in Dharma. (Edicts of Ashoka, 13th Rock Edict, S. Dhammika).
After the Greco-Bactrians militarily occupied parts of northern India from around 180 BCE, numerous instances of interaction between Greeks and Buddhism are recorded.
The conversion of Menander
Menander I, one of the most famous successors of Demetrius, ruled from 150 to 135 BCE. He is presented by Greek authors as an even greater conqueror than Alexander the Great. Strabo (XI.II.I) says Menander was one of the two Bactrian kings who extended their power farthest into India.
Menander, the "Saviour king", seems to have converted to Buddhism, and is described in Buddhist texts as a great benefactor of the religion, on a par with Ashoka or the future Kushan emperor Kanishka. He is famous for his dialogues with the Buddhist monk Nagasena, transmitted to us in the Milinda Panha, which explain that he became a Buddhist arhat:
"And afterwards, taking delight in the wisdom of the Elder, he handed over his kingdom to his son, and abandoning the household life for the house-less state, grew great in insight, and himself attained to Arahatship!" (The Questions of King Milinda, Translation by T. W. Rhys Davids)
Plutarch also presents Menander as an example of benevolent rule, and explains that upon his death, the honour of sharing his remains was claimed by the various cities under his rule, and they were enshrined in "monuments" (probably stupas), in a parallel with the historic Buddha:
"But when one Menander, who had reigned graciously over the Bactrians, died afterwards in the camp, the cities indeed by common consent celebrated his funerals; but coming to a contest about his relics, they were difficultly at last brought to this agreement, that his ashes being distributed, everyone should carry away an equal share, and they should all erect monuments to him." (Plutarch, "Political Precepts" Praec. reip. ger. 28, 6).
Buddhist proselytism
During the reign of Menander, the Greek (Pali: Yona, lit: "Ionian") Buddhist monk Mahadhammarakkhita (Sanskrit: Mahadharmaraksita, lit. "Great protector of the Dharma") is said to have come from Alasandra (thought to be Alexandria of the Caucasus, the city founded by Alexander the Great, near today's Kabul) with 30,000 monks for the foundation ceremony of the Maha Thupa ("Great stupa") built by king Dutthagamani at Anuradhapura in Sri Lanka, indicating the importance of Buddhism within Greek communities in northwestern India, and the prominent role Greek Buddhist monks played in them:
"From Alasanda the city of the Yonas came the thera (elder) Yona Mahadhammarakkhita with thirty thousand bhikkhus." (Mahavamsa, XXIX)
Several Buddhist dedications by Greeks in India are recorded, such as that of the Greek meridarch (civil governor of a province) named Theodorus, describing in Kharoshthi how he enshrined relics of the Buddha. The inscriptions were found on a vase inside a stupa, dated to the reign of Menander or one his successors in the 1st century BCE (Tarn, p391):
"Theudorena meridarkhena pratithavida ime sarira sakamunisa bhagavato bahu-jana-stitiye":
"The meridarch Theodorus has enshrined relics of Lord Shakyamuni, for the welfare of the mass of the people"
(Swat relic vase inscription of the Meridarkh Theodoros)
Although the spread of Buddhism to Central Asia and Northern Asia is usually associated with the Kushans, a century or two later, there is a possibility that it may have been introduced in those areas from Gandhara "even earlier, during the time of Demetrius and Menander" (Puri, "Buddhism in Central Asia"). There is however some textual evidence to suggest that Buddhism had penetrated much earlier to Central Asia, at least in a limited form: the first two disciples of the Buddha were named Tapassu and Bhallika, from the region of Balhika (the present Balkh, and Sanskrit for Bactria), and though it cannot necessarilly be presumed that any extensive prosyletization occurred on their return journey, that the Sanskrit name for Bactria derived from the name of a Bactrian-Buddhist disciple is suggestive of some early influence. Bhallika and Tapassu were both travellers, and if nothing else, the story of their conversion and their home region's Sanskrit nomenclature illustrates the possibility of early transmission via the local trade routes.
Buddhist symbolism
From around 180 BCE, Agathocles and Pantaleon, probable successors to Demetrius I in the Paropamisadae, and the earliest Greek kings to issue Indian-standard square bilingual coins (in Brahmi), depicted the Buddhist lion together with the Hindu goddess Lakshmi.
Some coins of Agathocles in the Indian standard also show a six-arched stupa and a tree in a railing, typical symbol of the Bodhi tree in early Buddhism [26]. These coins show an unprecedented willingness to adapt to every aspect of the local culture: shape of the coinage, coinage size, language, and religion.
Later, some Indo-Greek coins incorporate the Buddhist symbol of the eight-spoked wheel, such as those of Menander I, as well as his possible grandson Menander II. On these coins, the wheel is associated with the Greek symbols of victory, either the palm of victory, or the victory wreath handed over by the goddess Nike. This symbology has led some to conclude that Menander adopted the Buddhist mantle of a "Chakravartin" during his lifetime; lit., "one for whom the wheel of law turns," translated as "King of the Wheel" in Western texts.
The ubiquitous symbol of the elephant may or may not have been associated with Buddhism. Interestingly, on some coin series of Antialcidas, the elephant holds the same relationship to Zeus and Nike as the Buddhist wheel on the coin of Menander II, tending to suggest a common meaning for both symbols. Some of the earlier coins of king Apollodotus I directly associate the elephant with Buddhist symbolism, such as the stupa hill surmounted by a star, also seen, for example on the coins of the Mauryan Empire or those of the later Kuninda kingdom.
Conversely, the bull is probably associated with Shiva, and often described in an erectile state as on the coins of Apollodotus I.
Also, after the reign of Menander I, several Indo-Greek rulers, such as Agathokleia, Amyntas, Nicias, Peukolaos, Hermaeus, Hippostratos and Menander II, depicted themselves or their Greek deities forming with the right hand a symbolic gesture identical to the Buddhist vitarka mudra (thumb and index joined together, with other fingers extended), which in Buddhism signifies the transmission of the Buddha's teaching.
At precisely the same time, right after the death of Menander, several Indo-Greek rulers also started to adopt on their coins the Pali title of "Dharmikasa", meaning "follower of the Dharma" (the title of the great Indian Buddhist king Ashoka was Dharmaraja "King of the Dharma").[27] This usage was adopted by Strato I, Zoilos I, Heliokles II, Theophilos, Peukolaos, Menander II and Archebios.
Altogether, the conversion of Menander I to Buddhism suggested by the Milinda Panha seems to have triggered the use of Buddhist symbolism in one form or another on the coinage of close to half of the kings who succeeded him. Especially, all the kings after Menander who are recorded to have ruled in Gandhara (apart from the little known Demetrius III) display Buddhist symbolism in one form or another. On the contrary, none of the kings whose rule was limited to Punjab did display Buddhist signs (with the exception of the powerful Hippostratos, who probably took under his protection many Gandharan Greeks fleeing from the Indo-Scythians (Tarn).).
A 2nd century BCE relief from a Buddhist stupa in Bharhut, in eastern Madhya Pradesh (today at the Indian Museum in Calcutta), represents a foreign soldier with the curly hair of a Greek and the royal headband with flowing ends of a Greek king. In his left hand, he hold a branch of ivy, symbol of Dionysos. Also parts of his dress, with rows of geometrical folds, are characteristically Hellenistic in style. On his sword appears the Buddhist symbol of the three jewels, or Triratana.
Representation of the Buddha
The anthropomorphic representation of the Buddha is absent from Indo-Greek coinage, suggesting that the Indo-Greek kings may have respected the Indian aniconic rule for Buddhist depictions, limiting themselves to Buddhist symbolism only. Consistently with this perspective, the actual depiction of the Buddha would be a later phenomenon, usually dated to the 1st century CE, emerging from the sponsorship of the syncretic Kushan Empire and executed by Greek, and, later, Indian and possibly Roman artists. Datation of Greco-Buddhist statues is generally uncertain, but they are at least firmly established from the 1st century CE.
Another possibility is that the Indo-Greeks may not have considered the Buddha strictly as a God, but rather as an essentially human sage or philosopher, in line with the traditional Nikaya Buddhist doctrine. Just as philosophers were routinely represented in statues (but certainly not on coins) in Antiquity, the Indo-Greek may have initiated anthropomorphic representations of the Buddha in statuary only, possibly as soon as the 2nd-1st century BCE, as advocated by Foucher and suggested by Chinese murals depicting Emperor Wu of Han worshipping Buddha statues brought from Central Asia in 120 BCE (See picture). Foucher especially considered Hellenistic free-standing Buddhas as "the most beautiful, and probably the most ancient of the Buddhas", assigning them to the 1st century BCE, and making them the starting point of the anthropomorphic representations of the Buddha.[28]
The willingness of ancient Greeks to represent local deities is also attested in Egypt with the creation of the god Serapis in Hellenistic style, an adaptation of the Egyptian god Apis. An Indo-Chinese tradition also explains that Nagasena, also known as Menander's Buddhist teacher, created in 43 BCE in the city of Pataliputra a statue of the Buddha, the Emerald Buddha, which was later brought to Thailand.
Stylistically, Indo-Greek coins generally display a very high level of Hellenistic artistic realism, which declined drastically around 50 BCE with the invasions of the Indo-Scythians, Yuezhi and Indo-Parthians. The first known statues of the Buddha are also very realistic and Hellenistic in style and are more consistent with the pre-50 BCE artistic level seen on coins. This would tend to suggest that the first statues were created between 130 BCE (death of Menander) and 50 BCE, precisely at the time when Buddhist symbolism appeared on Indo-Greek coinage. From that time, Menander and his successors may have been the key propagators of Buddhist ideas and representations: "the spread of Gandhari Buddhism may have been stimulated by Menander's royal patronage, as may have the development and spread of Gandharan sculpture, which seems to have accompanied it" (Mc Evilly, "The shape of ancient thought", p378)
The representation of the Buddha may also be connected to his progressive deification, which is usually associated with the spread of the Indian principle of Bhakti (personal devotion to a deity). Bhakti is a principle which evolved in the Bhagavata religious movement, and is said to have permeated Buddhism from about 100 BCE, and to have been a contributing factor to the representation of the Buddha in human form. The association of the Indo-Greeks with the Bhagavata movement is documented in the inscription of the Heliodorus pillar, made during the reign of the Indo-Greek king Antialcidas (r.c. 115-95 BCE). At that time relations with the Sungas seem to have improved, and some level of religious exchange seems to have occurred. The point of time when bhakti fervour would have encountered the Hellenistic artistic tradition would then be around 100 BCE.
Most of the early images of the Buddha (especially those of the standing Buddha) are anepigraphic, which makes it difficult to have a definite datation. The earliest known image of the Buddha with approximate indications on date is the Bimaran casket, which has been found buried with coins of the Indo-Scythian king Azes II (or possibly Azes I), indicating a 30-10 BCE date,[29] although this date is not undisputed. Such datation, as well as the general Hellenistic style and attitude of the Buddha on the Bimaran casket (himation dress, contrapposto attitude, general depiction) would made it a possible Indo-Greek work, used in dedications by Indo-Scythians right after the end of Indo-Greek rule in the area of Gandhara. Since it already displays quite a sophisticated iconography (Brahma and Sakra as attendants, Bodhisattvas) in an advanced style, it would suggest much earlier representations of the Buddha were already current by that time, going back to the rule of the Indo-Greeks (Alfred A. Foucher and others).
Hinduism
The first known bilingual coins of the Indo-Greeks were issued by Agathocles around 180 BCE. These coins were found in Ai-Khanoum, the great Greco-Bactrian city in northeastern Afghanistan, but introduce for the first time an Indian script (the Brahmi script which had been in use under the Mauryan empire), and the first known representations of Hindu deities, in a very Indian iconography: Krishna-Vasudeva, with his large wheel with six spokes (chakra) and conch (shanka), and his brother Sankarshan-Balarama, with his plough (hala) and pestle (masala), both early avatars of Vishnu.[30] The square coins, instead of the usual Greek round coins, also followed the Indian standard for coinage. The dancing girls on some of the coins of Agathocles and Pantaleon are also sometimes considered as representations of Subhadra, Krishna's sister.
These first issues were in several respects a short-lived experiment. Hindu anthropomorphic deities were never again represented in Indo-Greek coinage (although the bull on the vast quantity of subsequent coins may have symbolized Shiva, as the elephant may have symbolized Buddhism), and the Brahmi script was immediately replaced by the Kharoshti script, derived from Aramaic. The general practice however of minting bilingual coins and combining Greek and Indian iconography, sometimes in the Greek and sometimes in the Indian standard continued for the next two centuries.
In any case, these coins suggest the strong presence of Indian religious traditions in the northwestern Indian subcontinent at that time, and the willingness of the Greeks to acknowledge and even promote them. Artistically, they tend to indicate that the Greeks were not particularly reluctant to make representations of local deities, which has some bearing on the later emergence of the image of the Buddha in Hellenistic style.
The Heliodorus pillar inscription is another epigraphical evidence of the interaction between Greeks and Hinduism. The pillar was erected around 110 BCE in central India at the site of Vidisha, by Heliodorus, a Greek ambassador of the Indo-Greek king Antialcidas to the court of the Sunga king Bhagabhadra. The pillar was surmounted by a sculpture of Garuda and was apparently dedicated by Heliodorus to the temple of Vasudeva.
Zoroastrianism
Persian culture and religion seem to have been rather influential among the Western Indo-Greeks, who, located around the Paropamisadae, lived in direct contact with the Central Asian cultural sphere and the eastern reaches of the Parthian empire. Images of the Persian Zoroastrian god Mithra appear extensively on the Indo-Greek coinage of the Western kings, as a god with a radiated phrygian cap.
This Zeus-Mithra god is also the one represented seated (with the rays around the head, and a small protrusion on the top of the head representing the cap) on many coins of Hermaeus, Antialcidas or Heliokles II, or possibly even earlier during the time of Eucratides I, on whose coins the deity is said to be the god of the city of Kapisa.
The future Buddha Maitreya, usually represented seated on a throne Western-style, and venerated both in Mahayana and non-Mahayana Buddhism, is sometimes considered as influenced by the god Mithra. "Some scholars suggest he (Maitreya) was originally linked to the Iranian saviour-figure Mitra, and that his later importance for Buddhist as the future Buddha residing in the Tusita heaven, who will follow on from Sakyamuni Buddha, derives from this source." (Keown, Dictionary of Buddhism)