Ur is mentioned many times in the Bible but it best known as the birthplace of Abraham. Ur is located in modern day Iraq and was located near the Euphrates River. It was one of the most ancient cities in existence believed to have been founded 6500 years ago.
Ur was the capital city of the Sumerian Empire, the first known empire of the world. During Abraham’s time, the city was at its height and it was probably the greatest city in the world at that time, around 2100 BC.
Ironically, or perhaps not so ironically since God knows what the future holds, the city of Ur was destroyed about 100 years after God called Abraham to leave the city. The city would be rebuilt and be mentioned several more times in scripture. Eventually it faded from prominence as the Euphrates River shifted course and the location became less important. Today Ur sits around twelve miles away from the Euphrates.
Ur is often mentioned as Ur of the Chaldeans. The Chaldeans didn’t arrive until long after Abraham’s time as they were precursors to the Babylonians. They came into being around 800 BC. They Chaldeans are likely mentioned as a reference to the land where Abraham was from, much like we would say Iraq today so that we have a modern frame of reference. Ur of the Chaldeans is not meant to imply that Abraham, coming from Ur, was a Chaldean.