An island group in the western Pacific Ocean east of the Philippines. Guam, the largest island of the group, is independent of the others, which are known formally as the Commonwealth of the Northern Mariana Islands. The Marianas were claimed by Magellan for Spain in 1521. They were sold to Germany in 1899 (when Guam was ceded to the United States) and later became a Japanese mandate (1919–1944).
Group of islands in the W Pacific Ocean, east of the Philippines: it includes Guam and the U.S. commonwealth of the Northern Mariana Islands: formerly (except Guam) a Japanese possession and (1947-86) part of the Trust Territory of the Pacific Islands.