Timor-Leste, officially the Democratic Republic of Timor-Leste, is a country in Southeast Asia and Oceania. The country comprises the eastern half of the island of Timor and the nearby islands of Atauro and Jaco. The first inhabitants are thought to be descendant of Australoid and Melanesian peoples. The Portuguese began to trade with Timor by the early 16th century and colonised it throughout the mid-century. Skirmishing with the Dutch in the region eventually resulted in an 1859 treaty for which Portugal ceded the western half of the island. Imperial Japan occupied East Timor during World War II, but Portugal resumed colonial authority after the Japanese surrender.