East Timor gained full independence At exactly midnight from May 19 to 20, the independence of East Timor was officially proclaimed. The newborn country was under Portuguese colonial rule for almost 400 years, was annexed by Jakarta for 24 years (from 1975 to 1999), and was ruled by the UN for the last two and a half years. Sergio Vieira de Mello, head of the UN administration, surrendered his powers to the country's first president, Xanana Gusmão.