The Northern Wei , also known as the Tuoba Wei (拓跋魏), Later Wei (後魏), or Yuan Wei (元魏), was a dynasty founded by the Tuoba clan of the Xianbei, which ruled northern China from 386 to 534 (de jure until 535), during the period of the Southern and Northern Dynasties. Described as "part of an era of political turbulence and intense social and cultural change", the Northern Wei Dynasty is particularly noted for unifying northern China in 439: this was also a period of introduced foreign ideas; such as Buddhism, which became firmly established. Many antiques and art works, both Daoist and Buddhist, from this period have survived. During the Taihe period (477-499) of Emperor Xiaowen, court advisers instituted sweeping reforms and introduced changes that eventually led to the dynasty moving its capital from Datong to Luoyang, in 494. It was the time of the construction of the Yungang Grottoes near Datong during the mid-to-late 5th century, and towards the latter part of the dynasty, the Longmen Caves outside the later capital city of Luoyang, in which more than 30,000 Buddhist images from the time of this dynasty have been found. The Tuoba renamed themselves the Yuan as a part of systematic Sinicization. Towards the end of the dynasty there was significant internal dissension resulting in a split into Eastern Wei and Western Wei.