Demetrius I's invasion of India

In 186 BCE, Demetrius I of Bactria invaded a crumbling Maurya Empire in the east. There are differing reasons for his invasion, but most scholars agree that saving the Greeks in India was the reason of his invasion

Demetrius I's invasion of India
Part of Greek campaigns in India
Date Late 2nd century BCE Location Sagala, Mathura, Patliputra Territorial changes Greeks lost Madhyadesa to Pushyamitra. Parts of the Punjab and the lower Sindhu valley was temporarily lost.
Belligerents
Greco-Bactrian Kingdom	Shunga Dynasty
Commanders and leaders
Demetrius I of Bactria	Pushyamitra Shunga
Strength
Unknown	Unknown

Invasion

Silver coin of Demetrius I. Diademed and draped bust of king, wearing elephant-skin headdress (evoking Alexander the Great and his conquests in India). Reverse shows Heracles standing, crowning himself, holding club and lion skin. Greek legend: ΒΑΣΙΛΕΩΣ ΔΗΜΗΤΡΙΟΥ, "of King Demetrius".

Demetrius I started the invasion following the destruction of the Mauryan dynasty by the general Pushyamitra Shunga, who then founded the new Indian Shunga dynasty (180–78 BC). Sri Lankan monks state that Brihadratha, the last Mauryan Emperor, married a daughter of Demetrius, Berenice. The Greco-Bactrians might have invaded the Indus Valley to protect Greek expatriates in the Indian Subcontinent.

Demetrius may have first started to recover the province of Arachosia, an area south of the Hindu Kush already inhabited by many Greeks but ruled by the Mauryas since the annexation of the territory by Chandragupta from Seleucus per Seleucid-Maurya treaty. In his Parthian stations, Isidorus of Charax mentions a colony named Demetrias, supposedly founded by Demetrius himself:

"Beyond is Arachosia. And the Parthians call this White India; there are the city of Biyt and the city of Pharsana and the city of Chorochoad and the city of Demetrias; then Alexandropolis, the metropolis of Arachosia; it is Greek, and by it flows the river Arachotus. As far as this place the land is under the rule of the Parthians." "Parthians stations", 1st century BC

The Greek campaigns may have gone as far as the capital Pataliputra in eastern India (today Patna):

"Those who came after Alexander went to the Ganges and Pataliputra" (Strabo, XV.698)

"The Greeks who caused Bactria to revolt grew so powerful on account of the fertility of the country that they became masters, not only of Ariana, but also of India, as Apollodorus of Artemita says: and more tribes were subdued by them than by Alexander — by Menander in particular (at least if he actually crossed the Hypanis towards the east and advanced as far as the Imaüs), for some were subdued by him personally and others by Demetrius, the son of Euthydemus the king of the Bactrians." (Strabo 11.11.1)

It is generally considered that Demetrius ruled in Taxila (where many of his coins were found in the archaeological site of Sirkap). The Indian records also describe Greek attacks on Saketa, Panchala, Mathura and Pataliputra (Gargi-Samhita, Yuga Purana chapter). However, the campaigns to Pataliputra are generally attested to the later king Menander I and Demetrius I probably only invaded areas in Pakistan. Other kings may have expanded the territory as well. By c. 175 BC, the Indo-Greeks ruled parts of northwestern India, while the Shungas remained in the Gangetic, Central, and Eastern India.

The Hathigumpha inscription of the Kalinga king Kharavela mentions that fearing him, a Yavana (Greek) king or general retreated to Mathura with his demoralized army. The name of the Yavana king is not clear, but it contains three letters, and the middle letter can be read as ma or mi. Some historians, such as R. D. Banerji and K.P. Jayaswal reconstructed the name of the Yavana king as "Dimita", and identified him with Demetrius. However, several other historians, such as Ramaprasad Chanda, Sailendra Nath Sen and P.L. Gupta disagree with this interpretation.

The first phase of the invasion ended here, followed by a civil war in Bactria. The Gargi-samhita states that the Yavanas who laid siege to Pushpapura did not remain in Madhyadesa for long due to "interregnum struggles, which escalated into "a cruel and dreadful war in their own kingdom." As a result, the Greeks seem to have lost control of Madhyadesa, as well as parts of the Punjab and the lower Sindhu valley, to Pushyamitra, at least temporarily. The King Demetrius returned back to Bactria leaving his governors to rule.

See also

• Shunga-Greek War