Timor was contacted by the Portuguese in 1515, and claimed as a territory of Portugal in 1520. The Dutch East India Company settled the west end of the island in 1640, pushing the Portuguese out and to the east side of the island. The Dutch government officially acknowledged their occupation in 1799, and an unsteady border was formed, separating the two sides. A treaty between the Portuguese and the Dutch was signed in 1859, and reformed in 1893, but it was not until as late as 1914 when the treaty was finalized and border disputes were finally laid to rest. Shortly after, in 1942, both sides of Timor were conquered by Empire of Japan during its invasion of the pacific. Timor participated in the Indonesian Interdependence cause, and joined the Republic of Indonesia in 1949. East Timor voted to leave the republic in 1999, becoming the first new sovereign nation of the 21st century.