The history of Nigeria can be traced to prehistoric settlers (Nigerians) living in the area as early as 1100 BC. Numerous ancient African civilizations settled in the region that is today Nigeria, such as the Kingdom of Nri, the Benin Empire, and the Oyo Empire. Islam reached Nigeria through the Borno Empire between (1068 AD) and Hausa States around (1385 AD) during the 11th century,[clarification needed] while Christianity came to Nigeria in the 15th century through Augustinian and Capuchin monks from Portugal. The Songhai Empire also occupied part of the region. Lagos was invaded 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 three years later 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 seized power again four years later. A new republic was planned to be established in 1993, but was dissolved by General Sani Abacha. Abacha died in 1998 and a fourth republic was later established the following year, which ended three decades of intermittent military rule.