Originally present-day Sierra Leone, is inhabited by the Sherbro, followed by the Temne, Limba and Susu. In 1462 the area is discovered by Portuguese explorers, they name the region Serra Lyoa, or Lion Mountain. English and Dutch settlers found trade factories, but the area is not taken in possesion by any European state. In 1562 the Temne tribes form the state of Temne. At the coast of the area the Freetown is founded in 1791 as a settlement for emancipated slaves, ruled by the Sierra Leone Company.

In 1808 the coastal area of Sierra Leone becomes a British crown colony. The hinterland becomes a British protectorate in 1896. In 1951 the colony gets a constitution, leading to self-government. Further self-government is granted in 1957 and an elected legislature is established. The Sierra Leone People's Party of Milton Margai wins the elections of 1957.

In 1961 Sierra Leone becomes independence with the British queen as head of state. It becomes a parliamentary democracy. The first elections under universal adult franchise in 1962 are won by the SLPP. After Milton Margai's death in 1964, he is succeeded by Albert Margai. In 1967 the All People's Congress (APC) of Siaka Stevens wins the elections. At that moment the army takes power, but a second coup leads in 1968 to the restoration to power of the elected prime minister Siaka Stevens.

He becomes president of the Republic of Sierra Leone in 1971 and eliminates the SLPP. In 1978 the APC becomes formally the sole party allowed in Sierra Leone. In 1985 Stevens is succeeded by Joseph Saidu Momoh, who begins in 1991 a transition to multiparty democracy. Under Momoh, APC rule is increasingly marked by abuses of power. The Revolutionary United Front (RUF) of Foday Sankoh starts a rebellion against the governement. In 1992 Valentine Strasser launches a military coup and establishes the National Provisional Ruling Council (NPRC) as the ruling authority in Sierra Leone. More and more country falls to RUF fighters. The regime succeeds in driving RUF fighters back to enclaves along Sierra Leone’s borders.

The NPRC agrees to hand over power to a civilian government via presidential and parliamentary elections, which are held in 1996. Ahmad Tejan Kabbah of the SLPP wins the presidential elections. The Armed Forces Revolutionary Council (AFRC) of Johnny Paul Koroma overthrow President Kabbah in 1997 and invite the RUF to join the government. The junta is ousted in 1998 by the Nigerian-led forces. Kabbah is reinstated. The rebels remain active. In 1999 a pease agreement is negotiated. It gives the RUF positions in government. When the RUF violates the agreement, the group is was stripped of its positions in government. The civil war continues until 2001. In 2002 Kabbah and his party, the SLPP, win a landslide victory.