The Prince of Achaea was the ruler of the Principality of Achaea, one of the crusader states founded in Greece in the aftermath of the Fourth Crusade (1202–1204). Though more or less autonomous, the principality was never a fully independent state, initially being a vassal state subservient of the Latin Empire of Constantinople, which had supplanted the Byzantine Empire, and later of the Angevin Kingdom of Naples. During the Angevin period, the princes were often absent, being represented in the Principality by their baillis, who governed in their name.