The historical sources of the Indo-Greek kingdom are very few, and the separation of kings with the same name is not an easy process. Numismatician Osmund Bopearachchi identifies three kings named Demetrius, placing the third around 100 BCE due to mintmarks and style of the coins (see discussion under Demetrius II). R C Senior agrees with this reconstruction, even though their dates are somewhat different: according to Bopearachchi he ruled around 100 BCE, whereas R. C. Senior places him circa 70 BCE, in both cases as successor of Heliokles II.