The history of the Barotse Kingdom begins with the southward movement of the Luyi people sometime around 1600. Luyi history is characterized by a series of expansionary conquests and the absorption of numerous other peoples under their rule. Luyi domination was temporarily interrupted when they were conquered by the Kololo, a group of invaders from the south, who ruled the kingdom from 1838 to 1864. In 1864 one of the Luyi (now known as Lozi) princes reestablished his group's dominance by conquering the Kololo. By then, however, British and Portuguese interests had begun to penetrate the area. The first treaties between the British and the Lozi, signed in 1890 and 1900, placed the Lozi under the authority of the British South Africa Company, but allowed them considerable autonomy in self-government. During the twentieth century, there were a series of changes in the larger political institutions to which the Lozi were subordinate. From 1924 to the 1950s, they were a part of Northern Rhodesia, under the rule of the British Colonial Office. Subsequently, they were incorporated into the Federation of Rhodesia and Nyasaland, and in 1964 Barotse Province became part of the newly proclaimed Republic of Zambia. Each of these political developments brought changes to the sociopolitical organization of the Lozi; the indigenous political organization increasingly lost power and functions, and the territorial extent of Lozi domination was constricted.