According to archaeological dating of associated artifacts and skeletal material, Cushitic speakers first settled in the lowlands of Kenya between 3,200 and 1,300 BC, a phase referred to as the Lowland Savanna Pastoral Neolithic. Nilotic-speaking pastoralists (ancestral to Kenya's Nilotic speakers) started migrating from present-day South Sudan into Kenya around 500 BC. Bantu people settled at the coast and in the interior of Kenya between 250 BC and 500 AD. European contact began in 1500 AD with the Portuguese Empire, though effective colonisation of Kenya began in the 19th century during the European exploration of the interior. Modern-day Kenya emerged from a protectorate established by the British Empire in 1895 and the subsequent Kenya Colony, which began in 1920. Numerous disputes between the UK and the colony led to the Mau Mau revolution, which began in 1952, and the subsequent declaration of independence in 1963. After independence, Kenya remained a member of the Commonwealth of Nations. The current constitution was adopted in 2010 to replace the 1963 independence constitution.