[2][3] He conquered large parts of northern India,[4] and minted a vast and prestigious coinage, suggesting a rule of considerable importance and prosperity.

[8][9][10] Whatever his origins, Eucratides came to power by overthrowing the Euthydemid dynasty in Bactria, possibly when its king, Demetrius was conquering northwestern India.

J. S. Watson[13]Having become master of Bactria after de-throning the Euthydemid dynasty, Eucratides was faced with a Parthian invasion which began when Demetrius I was conquering India.

Having taken Tapuria and Margiana from Demetrius in about 170 BC, the powerful Mithridates I attempted to conquer Bactria itself but was checked by Eucratides.

Once the Yuezhi tribes overpowered Heliocles, the Greco-Bactrians lost control of the provinces north of the Hindu Kush.

Other members of the dynasty were Plato of Bactria and probably Demetrius II, who in that case was not identical with the king Justin claimed was the enemy of Eucratides I.

Eucratides, however, carried on several wars with great spirit, and though much reduced by his losses in them, yet, when he was besieged by Demetrius king of the Indians, with a garrison of only three hundred soldiers, he repulsed, by continual sallies, a force of sixty thousand enemies.