The Autonomous Region in Muslim Mindanao (Tagalog: Rehiyong Awtonomo ng Muslim Mindanao; Arabic: الحكم الذاتي الاقليمي لمسلمي مندناو‎ Al-ḥukm adh-dhātī al-'iqlīmī li-muslimī Mindanāu;[3][4] abbreviated as ARMM) was an autonomous region of the Philippines, located in the Mindanao island group of the Philippines, that consisted of five predominantly Muslim provinces: Basilan (except Isabela City), Lanao del Sur, Maguindanao, Sulu, and Tawi-Tawi. It was the only region that had its own government. The region's de facto seat of government was Cotabato City, although this self-governing city was outside its jurisdiction.