According to local historiography, Brunei was founded by Awang Alak Betatar, later to be Sultan Muhammad Shah, reigning around AD 1400. He moved from Garang in the Temburong District to the Brunei River estuary, discovering Brunei. According to legend, upon landing he exclaimed, ''Baru nah'' (loosely translated as "that's it!" or "there"), from which the name "Brunei" was derived. He was the first Muslim ruler of Brunei. Before the rise of the Bruneian Empire under the Muslim Bolkiah Dynasty, Brunei is believed to have been under Buddhist rulers.