Among the oldest colonial cities of Africa, it was founded in January 1576 as ''São Paulo da Assunção de Loanda'' by Portuguese explorer Paulo Dias de Novais. The city served as the centre of the slave trade to Brazil before its prohibition. At the start of the Angolan Civil War in 1975, most of the white Portuguese left as refugees, principally for Portugal. Luanda's population increased greatly from refugees fleeing the war, but its infrastructure was inadequate to handle the increase. This also caused the exacerbation of slums, or musseques, around Luanda. The city is undergoing a major reconstruction, with many large developments taking place that will alter its cityscape significantly.