Luanda was Portugal's bridgehead from 1627, except during the Dutch rule of Luanda, from 1640 to 1648, as Fort Aardenburgh. The city served as the centre of slave trade to Brazil from circa 1550 to 1836. The slave trade was conducted mostly with the Portuguese colony of Brazil; Brazilian ships were the most numerous in the port of Luanda. This slave trade also involved local merchants and warriors who profited from the trade. During this period, no large scale territorial conquest was intended by the Portuguese; only a few minor settlements were established in the immediate hinterland of Luanda, some on the last stretch of the Kwanza River.