Madagascar is a republic which lies off the south-east coast of Africa and is the fourth largest island in the world. The country was uninhabited until the first wave of settlers arrived from the Indonesian archipelago around 350 BC via outrigger canoes. The diverse origins of the population of Madagascar are reflected in the mixed Malayo-Polynesian, Arab and east African heritage. European contact was made in 1500 when the Portuguese explorer Diogo Dias sighted the island while travelling to India on a trade mission. The French established trading colonies along the coast in the seventeenth century with mixed success. Between 1797 and 1861, Madagascar was unified as a kingdom under a dynasty of Merina nobles, but conflict with the French resulted in the establishment of a protectorate in 1895, and a the proclamation of a colony one year later. Madagascar became an Overseas Territory in 1946, and following a referendum was renamed the Malagasy Republic, achieving independence in 1960. The island has experienced a number of political crisis and four constitutional changes since the assassination of president Richard Ratsimandrava in 1975. The capital and largest city is Antananarivo. Estimated population of Madagascar in 2012 was 22,005,222.