Perhaps because the capital of Mitanni, Washukanni, has not yet been found, there are no available king lists, year lists, or royal inscriptions. Fortunately, a fair amount of diplomatic, Hittite, and Assyrian sources exist to firm up the chronology. Having become powerful under Shaushtatar, Mitanni eventually falls into the traditional trap of dynasties, the contest for succession. Tushratta and Artatama II both claim the kingship and the Hittites and Assyrians take advantage of the situation. After that, Mitanni was no longer a factor in the region.