The history of Nigeria can be traced to prehistoric settlers living in the area as early as 11,000 BC. Numerous ancient African civilizations settled in the region that is today Nigeria. An example of one of the civilizations that settles in Nigeria is the Nri Kingdom. Islam reached Nigeria through the Hausa States during the 11th century. The Songhai Empire also occupied part of the region. Lagos was captured by British forces in 1851 and formally annexed in 1861. Nigeria became a British protectorate in 1901. Colonization lasted until 1960, when an independence movement succeeded in gaining Nigeria its independence.
Nigeria first became a republic in 1963, but succumbed to military rule in 1966 after a bloody coup d'état. A separatist movement later formed the Republic of Biafra in 1967, leading to the three-year Nigerian Civil War. Nigeria became a republic once again after a new constitution was written in 1979. However, the republic was short-lived, when the military led by Major General Muhammadu Buhari seize again four years later. Buhari was overthrown and a new republic was founded in August 1993, but was dissolved once again by General Sani Abacha in November that same year. Abacha died in 1998 and a fourth republic was later established the following year, ending three decades of intermittent military rule.