The Gambia gained its independence from the UK in 1965. Geographically surrounded by Senegal, it formed a short-lived federation of Senegambia between 1982 and 1989. In 1991 the two nations signed a friendship and cooperation treaty, but tensions have flared up intermittently since then. Yahya Jammeh led a military coup in 1994 that overthrew the president and banned political activity. A new constitution and presidential elections in 1996, followed by parliamentary balloting in 1997, completed a nominal return to civilian rule. Jammeh has been elected president in all subsequent elections including most recently in late 2011.