At any rate, the Burmans had overtaken the leadership of the Pyu realm by the late 10th century, and went on to found the Pagan Empire in the middle of the 11th century, unifying the Irrawaddy valley and its periphery for the first time. Nonetheless, the Pyu had left an indelible mark on Pagan whose Burman rulers would incorporate the histories and legends of the Pyu as their own. The Burman kings of Pagan claimed descent from the kings of Sri Ksetra and Tagaung as far back as 850 BCE—a claim dismissed by most modern scholars. Pyu settlements remained in Upper Burma for the next three centuries but the Pyu gradually were absorbed and assimilated into the expanding Pagan Empire. The Pyu language still existed until the late 12th century but by the 13th century, the Pyu had assumed the Burman ethnicity and disappeared into history.