Kenya occupies 580,367 square kilometers on the East African coast where the equator crosses the Indian Ocean. The country shares borders with Somalia to the east, Ethiopia to the north, South Sudan to the northwest, Uganda to the west, and Tanzania to the south. Archaeological evidence from sites including Olorgesailie and Koobi Fora near Lake Turkana places human occupation in this territory at approximately 20 million years, with *Homo erectus* remains dated to 1.9 million years ago. The Turkana Boy fossil, discovered by Kamoya Kimeu in 1984 at Nariokotome near Lake Turkana, represents one of the most complete early hominin skeletons ever recovered, dated to approximately 1.5 million years. Richard and Meave Leakey led multiple excavations at Koobi Fora between 1968 and the present, yielding over 200 hominin fossils that established East Africa as central to human evolutionary studies. The National Museums of Kenya maintains custody of these specimens in Nairobi.
Bantu-speaking populations migrated into present-day Kenya from West Africa between 500 BCE and 500 CE. The Kikuyu, Kamba, Meru, Embu, and related groups settled the fertile central highlands surrounding Mount Kenya, which the Kikuyu call Kirinyaga. These agricultural communities developed terrace farming systems and maintained distinct age-set social structures. Nilotic peoples, including ancestors of the Maasai, Samburu, Turkana, and Kalenjin, migrated southward from the Nile Valley region between 500 CE and 1500 CE. The Maasai reached the Rift Valley by approximately 1700, establishing pastoralist economies centered on cattle. Cushitic-speaking groups, including the Somali, Rendille, and Borana, occupied the northern and eastern arid regions. Current population surveys by the Kenya National Bureau of Statistics identify 44 distinct ethnic groups, with no single group constituting a majority.
Arab traders established settlements along the Kenya coast beginning in the 8th century CE. Gede Ruins near Malindi preserve the remains of a Swahili town occupied from the 13th to 17th centuries, with a Friday mosque, palace structures, and imported Chinese porcelain dated through ceramic analysis to the Ming Dynasty. Lamu Old Town developed continuously from the 12th century as a center of Swahili architecture, with carved wooden doors, coral stone buildings, and narrow streets designed for donkey traffic. The Lamu Friday Mosque contains inscriptions dated to 1511. Portuguese explorer Vasco da Gama anchored at Malindi in April 1498 during his voyage to India. Portugal constructed Fort Jesus in Mombasa between 1593 and 1596 under the direction of Italian architect Giovanni Battista Cairati. The fort changed hands nine times between Portuguese and Omani forces before the Sultanate of Oman secured permanent control in 1698. UNESCO designated Fort Jesus as a World Heritage Site in 2011.
Sultan Seyyid Said of Oman relocated his capital from Muscat to Zanzibar in 1840, extending Omani influence over coastal Kenya through appointed governors. The Mazrui family governed Mombasa under Omani suzerainty while maintaining significant autonomy. Interior trade routes extended from Mombasa to Lake Victoria by the 1850s, with caravans exchanging coastal goods for ivory and later slaves from interior regions. Johann Ludwig Krapf and Johannes Rebmann, missionaries with the Church Missionary Society, established a mission at Rabai near Mombasa in 1846. Rebmann documented the first European sighting of Mount Kilimanjaro in May 1848. Joseph Thomson traversed Maasai territory in 1883-1884, reaching Lake Victoria through the Rift Valley. The Imperial British East Africa Company received a royal charter in 1888 to administer territory between the coast and Uganda.
Britain declared the East Africa Protectorate on July 1, 1895, with jurisdiction over the coastal strip leased from the Sultan of Zanzibar and interior territories extending to Uganda. The Uganda Railway, connecting Mombasa to Kisumu on Lake Victoria, commenced construction in 1896 under chief engineer George Whitehouse. Indian laborers, numbering approximately 32,000 according to railway company records, built the 660-mile line completed in December 1901. Construction costs totaled £5.5 million. Colonel John Henry Patterson documented man-eating lions killing approximately 35 railway workers at Tsavo between March and December 1898. Nairobi originated as a railway depot and construction camp in 1899 at mile 327. The colonial administration transferred the protectorate capital from Mombasa to Nairobi in 1905.
White settler immigration increased after 1902 when the colonial government made Crown lands available for long-term lease in the highlands above 7,500 feet elevation. The 1915 Crown Lands Ordinance formalized racial land allocation, reserving the White Highlands for European agriculture. Settlers established large-scale coffee, tea, and sisal plantations using African labor under the kipande pass system introduced in 1915. Karen Blixen managed a coffee farm at the foot of the Ngong Hills from 1914 to 1931, documented in her memoir "Out of Africa" published in 1937. Indian merchants and traders, many originally associated with railway construction, established commercial networks in Nairobi and provincial towns. By 1920, when the territory became Kenya Colony, the population included approximately 9,651 Europeans, 22,822 Indians, and an estimated 2.5 million Africans according to colonial census data.
The Kikuyu Central Association formed in 1924 to advocate for land rights and political representation. Johnstone Kamau, later known as Jomo Kenyatta, became KCA general secretary in 1928. Kenyatta traveled to London in 1929 to present Kikuyu grievances regarding land alienation to the Colonial Office. He remained in Britain until 1946, studying anthropology at the London School of Economics under Bronisław Malinowski and publishing "Facing Mount Kenya" in 1938. The Kenya African Union, formed in 1944 as the successor to banned pre-war political organizations, elected Kenyatta as president in 1947. The organization demanded expanded African representation on the Legislative Council, which in 1948 included 11 appointed Europeans, 5 appointed Asians, 1 appointed Arab, and 4 appointed Africans.
Armed resistance against colonial rule began in the central highlands and Nairobi in 1952, later termed the Mau Mau uprising by colonial authorities. Fighters took oaths binding them to secret military organizations operating from forest bases in the Aberdare Range and Mount Kenya. On October 20, 1952, Governor Evelyn Baring declared a State of Emergency. Security forces arrested Kenyatta and five other KAU leaders on October 21, 1952, charging them with managing Mau Mau. A trial at Kapenguria concluded in April 1953 with guilty verdicts and seven-year sentences. Colonial forces detained approximately 80,000 suspected Mau Mau supporters in camps, according to documents later released from British archives. The Emergency formally ended on January 12, 1960, though armed conflict had largely ceased by 1956. Historians debate casualty figures. The colonial government recorded 11,503 Mau Mau killed, 63 European civilians killed, and 32 European security force members killed. Post-independence Kenyan estimates range substantially higher for African casualties.
Constitutional conferences at Lancaster House in London during 1960, 1962, and 1963 negotiated independence terms. Kenyatta was released from detention on August 14, 1961, and elected president of the Kenya African National Union in 1961. KANU won 83 of 124 seats in the May 1963 legislative elections. Kenya achieved internal self-government on June 1, 1963, with Kenyatta as prime minister. Full independence came at midnight on December 12, 1963. Kenya became a republic on December 12, 1964, with Kenyatta as president. He held office until his death on August 22, 1978.