Why did the city of Babylon become the main one in Mesopotamia? When did it happen?

The city of Babylon in the ancient world was a very developed cultural and commercial center in the Middle East. It flourished during the reign of King Nebuchadnezzar II (605-562 BC), when the Babylonian state was revived. In fact, then the city became one of the most majestic and richest in the ancient world. Even centuries later, Alexander the Great himself was captured by its beauty and grandeur when he entered Babylon. His impression was so great that he decided to make this city the capital of his empire.