The World War II Battle of Guadalcanal was the first major invasion and a significant victory for the Allies in the Pacific theater. Strategically, possession of a Guadalcanal air base was very important to take control of the sea lines of communication between the United States and Australia. In 1942 the Japanese Empire stretched over a large area of the Western Pacific and by Spring Japanese troops swept through the Solomon Islands. By the end of May, Japanese territories spread to the large jungle islands that gave its name to the best known episode of the Pacific War, Guadalcanal. In early June the American victory at Midway persuaded Japanese forces to halt their expansion into the Pacific.