In the South Western Pacific the Allies now seized the strategic initiative for the first time during the War and in June 1943, launched Operation Cartwheel, a series of amphibious invasions to recapture the Solomon Islands and New Guinea and ultimately isolate the major Japanese forward base at Rabaul. Following the Japanese Invasion of Salamaua–Lae in March, 1943, Cartwheel began with the Salamaua–Lae campaign in Northern New Guinea in April, 1943, which was followed in June to October by the New Georgia campaign, in which the Allies used the Landings on Rendova, Drive on Munda Point and Battle of Munda Point to secure a secretly constructed Japanese airfield at Munda and the rest of New Georgia Islands group. Landings from September until December secured the Treasury Islands and landed Allied troops on Choiseul, Bougainville and Cape Gloucester.