The Kingdom of Sitawaka (Sinhala: සීතාවක) was a kingdom located in south-central Sri Lanka. It emerged from the division of the kingdom of Kotte following the Spoiling of Vijayabahu in 1521, and over the course of the next seventy years came to dominate much of the island. Sitawaka also offered fierce resistance to the Portuguese, who had arrived on the island in 1505. Despite its military successes, Sitawaka remained unstable, having to contend with repeated uprisings in its restive Kandyan territories, as well as a wide-ranging and often devastating conflict with the Portuguese. Sitawaka disintegrated soon after the death of its last king Rajasimha I in 1594.
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 VII 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.
The kingdom of Sitawaka initially covered a relatively small area including Kosgama, Ruwanwella, Yatiyanthota, Hanwella, Padukka, Ehaliyagoda, Kuruwita and Rathnapura. The terrain was hilly, bordered to the east by Kandy and with no access to the sea. The capital city—modern Avissawella—was situated on a steep hill at the base of bluff hills rising around 1,000 feet (300 m) above the surrounding jungle cover.
Following the fall of Sitawaka, Portuguese forces sacked the city and pressed inland until they were expelled by Kandyan forces under Vimaladharmasuriya. The Portuguese remained the premier power in lowland Sri Lanka until the early 17th century, when they were finally expelled by Rajasinha II and his Dutch allies.
A resurgent kingdom of Kandy under Vimaladharmasuriya I also sacked Sitawaka, and went on to become the major source of resistance to European power for the next two hundred years. Avissawella was reduced to being a border town, and the royal complex was eventually lost to the jungle until explored by the British in the 19th century.
“ Sitawaka, once a royal residence, and a place of considerable consequence, is now merely a name. No traces of what it once was are now to be seen by the traveller passing along the road; and for a time none were supposed to exist.Only the platform remains, quite small within a moat crossed by a bridge of massive slabs. The wall of the platform is gloriously simple, with delicate flowered fillet, a garland of stone that must be seen to be appreciated. Apart from the fillet, the chief ornaments are pilasters, separated by perfectly flat areas which had to be cut away in order to leave the pilasters in relief; and on one of the flats is an odd little parrot, entirely unrelated to anything in the design. It seems obvious, and quite delightful, that the workmen got fed up with recessing that flat surface and left the birds in relief for fun, to be chiselled away on a morrow that never (John Davy, An Account of the Interior of Ceylon, 1812)