Settled by both Britain and France during the first half of the 19th century, the island became a French possession in 1853. It served as a penal colony for four decades after 1864. Agitation for independence during the 1980s and early 1990s ended in the 1998Noumea Accord, which over the past 20 years has transfered an increasing amount of governing responsibility from France to New Caledonia. The agreement also commits France to conduct a referendum by November 2018 for residents to decide whether New Caledonia should assume full sovereignty and independence.