The Indo-Greek kings introduced Greek types, among them the portrait head, into the Indian coinage, and their example was followed for eight centuries. The Indo-Greek kings introduced Greek types, among them the portrait head, into the Indian coinage, and their example was followed for eight centuries. The extensive coinage of the Kushan Empire (1st–3rd centuries CE) continued to influence the coinage of the Guptas (320–550 CE) and the later rulers of Kashmir. Kushan coins had the diademed, helmeted bust of the king on one side and the king’s favourite deity on the reverse.