Eucratides I (Greek: Εὐκρατίδης Α΄; reigned c. 171–145 BC), was one of the most important Greco-Bactrian kings. He overthrew the Diodotid dynasty of Bactria and replaced it with his own, causing a civil war, in which he fought against the Diodotid Indo-Greek kings, the easternmost Hellenistic rulers in India, temporarily holding territory as far as the Indus, until he was finally defeated and pushed back to Bactria. A split in the once powerful Bactrian Empire formed two separate Greek states, ruled by the Eucratidids in Bactria and the Diodotids in India. Eucratides had a vast and prestigious coinage, suggesting a rule of considerable importance.