The Babylonian king was planning on reasserting his power in Syria. In 609 BC, King Nabopolassar captured Kumukh, which cut off the Egyptian army, then based at Carchemish. Necho responded the following year by retaking Kumukh after a four-month siege, and executed the Babylonian garrison. Nabopolassar gathered another army, which camped at Qurumati on the Euphrates. However, Nabopolassar's poor health forced him to return to Babylon in 605 BC. In response, in 606 BC the Egyptians attacked the leaderless Babylonians (probably then led by the crown prince Nebuchadrezzar) who fled their position.