Known today as Tell el-Muqayyar, the 'Mound of Pitch', the site was occupied from around 5000 BC to 300 BC. Although Ur is famous as the home of the Old Testament patriarch Abraham (Genesis 11:29-32), there is no actual proof that Tell el-Muqayyar was identical with 'Ur of the Chaldees'. In antiquity the city was known as Urim.
The main excavations at Ur were undertaken from 1922-34 by a joint expedition of The British Museum and the University Museum, Pennsylvania, led by Leonard Woolley. At the centre of the settlement were mud brick temples dating back to the fourth millennium BC. At the edge of the sacred area a cemetery grew up which included burials known today as the Royal Graves. An area of ordinary people's houses was excavated in which a number of street corners have small shrines. But the largest surviving religious buildings, dedicated to the moon god Nanna, also include one of the best preserved ziggurats, and were founded in the period 2100-1800 BC. For some of this time Ur was the capital of an empire stretching across southern Mesopotamia. Rulers of the later Kassite and Neo-Babylonian empires continued to build and rebuild at Ur. Changes in both the flow of the River Euphrates (now some ten miles to the east) and trade routes led to the eventual abandonment of the site.