This coin is part of the very elusive Bactrian series of which most of their existence is unknown apart from their coinage. The Bactrian empire was founded in c. 256 BC by the Seleucid satrap Diodotus I Soter. However, much of the earliest population were Greeks that were exiled there from other parts of the Greek world. Initially, Greeks from Barca in Cyrenaica, that were forced to leave their homeland under the Persian ruler Darius I. The area of Bactria (which constitutes current day Afghanistan, Pakistan, and Tajikistan) flourished as a center of Greek trade and commerce. It was also an important trade route between the east and the west. 

This coin shows three major figures in the Bactrian dynasty, Eukratides I Megas, Heliokles and Laodike. Heliokles was the brother to Eukratides (the Great) who was responsible for bringing the Bactrian region back under the auspices of the Diodotids. Laodike was his wife. They were considered to be the last Greco-Bactrian rulers of Bactria. Thus, stylistically the coinage reflects a more classical style versus the marked change with later Bactrian rulers.