From 1942 until the end of 1943, the Solomon Islands were the scene of several major land, sea and air battles between the Allies and the Japanese Empire's armed forces. Following the Japanese attack on Pearl Harbour in 1941 war was declared between Japan and the Allied Powers, and the Japanese, seeking to protect their southern flank, invaded South-East Asia and New Guinea. In May 1942 the Japanese launched Operation Mo, occupying Tulagi and most of the western Solomon Islands, including Guadalcanal where they began work on an airstrip. The British administration had already relocated to Auki, Malaita and most of the European population had been evacuated to Australia. The Allies counter-invaded Guadalcanal in August 1942, followed by the New Georgia campaign in 1943, both of which were turning points in the Pacific War, stopping and then countering the Japanese advance. The conflict resulted in thousands of Allied, Japanese and civilian deaths, as well an immense destruction across the islands.