Within the Indo-Greek Kingdom there were over 30 kings, often in competition on different territories. Many of them are only known through their coins. Many of the dates, territories, and relationships between Indo-Greek kings are tentative and essentially based on numismatic analysis (find places, overstrikes, monograms, metallurgy, styles), a few Classical writings, and Indian writings and epigraphic evidence. The following list of kings, dates and territories after the reign of Demetrius is derived from the latest and most extensive analysis on the subject, by Osmund Bopearachchi ("Monnaies Gréco-Bactriennes et Indo-Grecques, Catalogue Raisonné", 1991).