The Kingdom of Sitawaka (Sinhala: සීතාවක) was a kingdom located in south-central Sri Lanka. Based at the city of Sitawaka, the kingdom soon came to dominate the neighbouring kingdoms of Kotte, Raigama, and Kandy, and successfully restricted Portuguese colonial power to the south-west coast of the island of Sri Lanka. Despite its successes, however, the polity disintegrated soon after the death of its last king Rajasimha I, leading to renewed Portuguese expansion on the island.
The Kingdom of Kotte had been the major power in western Sri Lanka since its foundation in the early 15th century; under Parakaramabahu VI, the polity has been the last to unite the entirety of the island of Sri Lanka under one crown. By 1467, however, the Jaffna Kingdom to the north had asserted its independence. In 1505 the first Portuguese arrived in Sri Lanka; by 1518 a large fleet of Portuguese ships had landed at Colombo and begun to construct a fort known as Santa Bárbara. To the east, the client kingdom of Kandy was by this time operating with a considerable degree of independence as well.
Vijayabahu VI of Kotte (1509 – 1521) was deposed in a palace coup known as the Spoiling of Vijayabahu in 1521 by his three sons who feared their succession to the throne was about to be overlooked in favour of Vijayabahu’s fourth son, Devaraja. The eldest succeeded him to the throne as Buvanekabahu VII, whilst the other two claimed parts of Kotte for themselves – Mayadunne ruling from Sitawaka and Pararajasinha establishing the kingdom of Raigama. The kingdom of Kandy was effectively outside of the control of any of these three successor states.