Indo-Greek Kingdom or Greco-Indian Kingdom was ruled by more than 30 Hellenistic kings at the various parts of the northwest and northern Indian subcontinent during a period from the 2nd century BCE to the beginning of the 1st century CE. They were often in conflict with each other.
The Greco-Bactrian king Demetrius invaded India early in the second century BCE; and formed the kingdom, in this context at the boundary of India. There were numerous cities, such as Taxila, Pakistan's Punjab, or Pushkalavati, Sagala and a number of dynasties in their times based on Ptolemy's Geography and the nomenclature of later kings.
The Indo- Greeks remained in India for two centuries (up to the 1st century CE) and later paving the way for the Shakas (Scythians), Pahlavas (Parthians) and the Kushanas (Yuezhi).
Demetrius, son of the Greco-Bactrian king Euthydemus I, led his troops across the Hindu Kush around 200 BCE when the invasion of northern India, and the establishment of "Indo-Greek kingdom" started. Apollodotus, may have made advances in the south, while Menander, led later invasions further east.
The Bactrian king Euthydemus and his son Demetrius crossed the Hindu Kush and began the conquest of Northern Afghanistan and the Indus valley. They wielded great power: a great Greek empire seemed to have arisen far in the East. But this empire was fallen off by internal argument and continual usurpations. When Demetrius advanced far into India, one of his generals, Eucratides, made himself king of Bactria, and soon in every province there arose new usurpers, who proclaimed themselves kings and fought one against the other.
Most of them were from Afghanistan, Pakistan and India and known only by their coins. By these wars, the dominant position of the Greeks was weakened even more quickly than would otherwise have been the case. After Demetrius and Eucratides, the kings abandoned the Attic standard of coinage and introduced a native standard, no doubt to gain support from outside the Greek minority.
In India, Milinda/ Menander I the Indo-Greek king, converted to Buddhism. His successors managed to cling to power until the last known Indo-Greek ruler, a king named Strato II, who ruled in the Punjab region until around 55 BCE. However, other sources place the end of Strato II's reign as late as 10 CE.
Written evidence of the initial Greek invasion survives in the Greek writings of Strabo and Justin and in Sanskrit in the records of Patanjali, Kālidāsa, and in the Yuga Purana, among others. Coins and architectural evidence also attest to the extent of the initial Greek campaign.
They ruled for two centuries, combined the Greek and Indian languages and symbols which can be seen on their coins, and blended ancient Greek, Hindu and Buddhist religious practices, as seen in the archaeological remains of their cities.
The Indo-Greeks ultimately disappeared as a political entity around 10 CE following the invasions of the Indo-Scythians, although pockets of Greek populations probably remained for several centuries longer under the subsequent rule of the Indo-Parthians and Kushans.
Literature
Various Indian records describe Yavana attacks on Mathura, Panchala, Saketa, and Pataliputra. The term Yavana is thought to be a transliteration of "Ionians" and is known to have designated Hellenistic Greeks (starting with the Edicts of Ashoka, where Ashoka writes about "the Yavana king Antiochus"), but may have sometimes referred to other foreigners as well after the 1st century CE.Patanjali, a grammarian and commentator on Panini around 150 BCE, describes in the Mahābhāsya, the invasion in two examples using the imperfect tense of Sanskrit, denoting a recent event: "Arunad Yavanah Sāketam" and "Arunad Yavano Madhyamikām".
Also the Brahmanical text of the Yuga Purana, which describes Indian historical events in the form of a prophecy, but is thought to be likely historical, 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.
After the Greco-Bactrians militarily occupied parts of northern India from around 180 BCE, numerous instances of interaction between Greeks and Buddhism are recorded.
Religion
Besides the worship of the Classical pantheon of the Greek deities found on the coins (Zeus, Herakles, Athena, Apollo), the Indo-Greeks were involved with local faiths, particularly with Buddhism, but also with Hinduism and Zoroastrianism.Menander I, converted to Buddhism, and is described as a great benefactor of the religion, on a par with Ashoka or the future Kushan emperor Kanishka. The wheel he represented on some of his coins was probably Buddhist, and 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
Another Indian text, the Stupavadana of Ksemendra, mentions in the form of a prophecy that Menander will build a stupa in Pataliputra. 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" (μνημεία, probably stupas), in a parallel with the historic Buddha.
Art
In general, the art of the Indo-Greeks is poorly documented, and few works of art (apart from their coins and a few stone palettes) are directly attributed to them. The coinage of the Indo-Greeks however, is generally considered as some of the most artistically brilliant of Antiquity. The Hellenistic heritage (Ai-Khanoum) and artistic proficiency of the Indo-Greek world would suggest a rich sculptural tradition as well, but traditionally very few sculptural remains have been attributed to them. On the contrary, most Gandharan Hellenistic works of art are usually attributed to the direct successors of the Indo-Greeks in India in 1st century CE, such as the nomadic Indo-Scythians, the Indo-Parthians and, in an already decadent state, the Kushans. In general, Gandharan sculpture cannot be dated exactly, leaving the exact chronology open to interpretation.
The possibility of a direct connection between the Indo-Greeks and Greco-Buddhist art has been reaffirmed recently as the dating of the rule of Indo-Greek kings has been extended to the first decades of the 1st century CE, with the reign of Strato II in the Punjab. Also, Foucher, Tarn, and more recently, Boardman, Bussagli and McEvilley have taken the view that some of the most purely Hellenistic works of northwestern India and Afghanistan, may actually be wrongly attributed to later centuries, and instead belong to a period one or two centuries earlier, to the time of the Indo-Greeks in the 2nd-1st century BCE.
This also seems to be corroborated by Ranajit Pal's suggestion that the Indo-Greek king Diodotus I was the great Ashoka.
Afghanistan, an area which "might indeed be the cradle of incipient Buddhist sculpture in Indo-Greek style"
Referring to one of the Buddha triads in Hadda, in which the Buddha is sided by very Classical depictions of Herakles/Vajrapani and Tyche/Hariti, Boardman explains that both figures "might at first (and even second) glance, pass as, say, from Asia Minor or Syria of the first or second century BCE (...) these are essentially Greek figures, executed by artists fully conversant with far more than the externals of the Classical style".
Alternatively, it has been suggested that these works of art may have been executed by itinerant Greek artists during the time of maritime contacts with the West from the 1st to the 3rd century CE.
The Greco-Buddhist art of Gandhara, beyond the omnipresence of Greek style and stylistic elements which might be simply considered as an enduring artistic tradition, offers numerous depictions of people in Greek Classical realistic style, attitudes and fashion (clothes such as the chiton and the himation, similar in form and style to the 2nd century BCE Greco-Bactrian statues of Ai-Khanoum, hairstyle), holding contraptions which are characteristic of Greek culture (amphoras, "kantaros" Greek drinking cups), in situations which can range from festive (such as Bacchanalian scenes) to Buddhist-devotional.
Uncertainties in dating make it unclear whether these works of art actually depict Greeks of the period of Indo-Greek rule up to the 1st century BCE, or remaining Greek communities under the rule of the Indo-Parthians or Kushans in the 1st and 2nd century CE. Benjamin Rowland thinks that the Indo-Greeks, rather than the Indo-Scythians or the Kushans, may have been the models for the Bodhisattva statues of Gandhara.
Economy
Very little is known about the economy of the Indo-Greeks, although it seems to have been rather vibrant. The abundance of their coins would tend to suggest large mining operations, particularly in the mountainous area of the Hindu-Kush, and an important monetary economy. The Indo-Greek did strike bilingual coins both in the Greek "round" standard and in the Indian "square" standard, suggesting that monetary circulation extended to all parts of society. The adoption of Indo-Greek monetary conventions by neighbouring kingdoms, such as the Kunindas to the east and the Satavahanas to the south, would also suggest that Indo-Greek coins were used extensively for cross-border trade.
Trade with China
An indirect testimony by the Chinese explorer Zhang Qian, who visited Bactria around 128 BCE, suggests that intense trade with Southern China was going through northern India. Zhang Qian explains that he found Chinese products in the Bactrian markets, and that they were transiting through northwestern India, which he incidentally describes as a civilization similar to that of Bactria.
Indian Ocean trade
Maritime relations across the Indian ocean started in the 3rd century BCE, and further developed during the time of the Indo-Greeks together with their territorial expansion along the western coast of India. By the time Indo-Greek rule was ending, up to 120 ships were setting sail every year from Myos Hormos to India.
Armed forces
The coins of the Indo-Greeks provide rich clues on their uniforms and weapons. Typical Hellenistic uniforms are depicted, with helmets being either round in the Greco-Bactrian style, or the flat kausia of the Macedonians (coins of Apollodotus I).
Military technology
Their weapons were spears, swords, longbow (on the coins of Agathokleia) and arrows. The recurve bow becomes a standard feature of Indo-Greek horsemen by 90 BCE, as seen on some of the coins of Hermaeus.
Generally, Indo-Greek kings are often represented riding horses, as early as the reign of Antimachus II around 160 BCE. The equestrian tradition probably goes back to the Greco-Bactrians, who are said by Polybius to have faced a Seleucid invasion in 210 BCE with 10,000 horsemen. War elephants were never represented on their coins.
Source ~History of India