Basilan, officially the Province of Basilan, is an island province of the Philippines located primarily in the Bangsamoro Autonomous Region. It is the largest and northernmost of the major islands in the Sulu Archipelago. Basilan lies just off the southern coast of the geographic Zamboanga Peninsula of Mindanao, across the Basilan Strait. The island is known for its diverse ethnolinguistic groups, including the indigenous Yakans, Tausugs, and Chavacanos. While the official languages are Filipino and English, the main native language is Yakan, and the lingua franca is Chavacano. Basilan has one of the lowest incidences of poverty in the Philippines and is classified as a 3rd-class province in terms of gross provincial income