Sumba had always been an isolated island. It was inhabited by several small ethno linguistic groups. Sumba had its own civilization. There were small clans or kingdoms with their own customs, own social structures, and ceremonies during the cycle of life such as birth (habola), marriage (Mangoma lalei), and death (pa taningu).
In the fourteenth century, Sumba was part of the Javanese Majapahit dynasty. After this dynasty had collapsed, Sumba came under the rule of Bima in Sumbawa and later Gowa in Sulawesi. These political changes had little impact on daily life in Sumba. Life was more influenced by internal wars between the clans and small kingdoms because of land and trading rights.
In 1522 the first ships of the Portuguese people came here. The Netherlands, later the colonialists of Indonesia, initially gave little attention to Sumba because they saw no significant commercial interests in Sumba. Also the large number of small kingdoms made it hard to install a significant impact. The Netherlands did not discover the value of sandalwood until the 18th century and then started interfering in Sumba. In 1756 a treaty was made between the Dutch United East India Company (VOC) and some of the Sumbanese nobles.
During the Second World War Sumba was occupied by the Japanese from 1942 to 1945. The Japanese intended to use Sumba as a starting point for an invasion of Australia. The Sumbanese say that the rule of the Japanese was more brutal than the Dutch.The Japanese left Sumba when the Australians landed in the south of the island.
The news of Sukarno having declared independence in 1945 took 6 months to reach Sumba. Exactly 5 years later on 17 August 1950 Indonesia took over Sumba as well as other island in east Indonesia. Sumba got part of the province of Nusa Tenggara Timur.