Brigadier David Lansana (1922–1975) was one of the very few Sierra Leoneans to be educated at the Royal Military Academy, Sandhurst, England during the colonial period. As Lieutenant David Lansana he was a frequent and popular visitor to the home of Sir Robert de Zouche Hall, Governor of Sierra Leone 1952-1956. He was appointed army commander of Sierra Leone in 1964. Brigadier Lansana took control of the army from British colonial adviser, Brigadier R.D. Blackie when Lansana's close ally Prime Minister Albert Margai came to power. He came from the Mende tribe as did Margai and conflicts existed between northern tribes, the Krios and the Mendes.
In 1967 Margai, who promoted a one party (non-democratic) state was beaten in a general election. Lansana staged a brief coup, arresting Siaka Stevens, the democratic winner of the election and the army was purged of Northern and Krio officers. No trials were ever held. Even after this he was unpopular with many of his fellow Mende officers who did not believe the army should be a tool of internal government. Subsequently Lt.-Colonel Andrew Juxon-Smith, of the Krio community, who was abroad when the coup took place, was asked to head the military regime the National Reformation Council, NRC in 1968. In 1975 Lansana was executed for treason.