After the Marianas, Palau was the most modernized and prosperous island group in Micronesia during Japanese rule. But life had changed for everyone during the early years of the war. As Allied bombing raids intensified, Koror was evacuated and most of its people sent to Babeldaob. Japanese defense forces dug in, as US troops swept westward during 1944, taking the Gilberts and then the Marshalls. By the end of the summer, Saipan and Tinian and Guam had also fallen to the Allies. Palau, with its airbases on Angaur and Peleliu, would be the next target for invasion. War was inevitable.