The failure of the Japanese to take Port Moresby and their defeat at Midway had the effect of leaving their base at Tulagi without effective protection from other Japanese bases. Tulagi was four hours flying time from Rabaul, the nearest large Japanese base. On 7 August 1942, 11,000 U.S. Marines landed on Guadalcanal and 3,000 U.S. Marines landed on Tulagi and nearby islands. The Japanese troops on Tulagi and nearby islands were outnumbered and killed almost to the last man in the Battle of Tulagi and Gavutu-Tanambogo while the U.S. Marines on Guadalcanal captured the airfield at Lunga Point without significant resistance. Thus began the Guadalcanal campaign that resulted in a series of large, combined-arms battles between Allied and Japanese forces over the next six months which—along with the New Guinea campaign—would decide the fate of Japanese efforts to secure the southern frontier of their empire in the Pacific.