The abolition of the slave trade coincided with increased Portuguese expansion in Angola. Expansion began in 1838 with the conquest and establishment of a fort at Duque de Bragança (renamed Calandula), in an area east of Luanda. By mid-century the Portuguese had extended their formal control still farther east to the Kasanje market near the Cuango River (see Matamba and Kasanje Kingdoms , this ch.). In 1840 the Portuguese founded the town of Moçâmedes (present-day Namibe) on the coast south of Benguela. The Portuguese also attempted to gain control of the coast from Luanda north to Cabinda through military occupation of the major ports. Because of British opposition, however, they were unable to complete this attempt and never gained control of the mouth of the Congo River.

The cost of military operations to secure economically strategic points led in 1856 to the imposition on Africans of a substantially increased hut tax, which for the first time had to be paid with currency or trade goods rather than with slaves. As a result, many Africans either refused to pay or fled from areas controlled by the Portuguese. By 1861, therefore, the Portuguese lacked the resources for continued military expansion or economic development, and most of the interior remained in the control of African traders and warriors.

From the late 1870s through the early 1890s, Portugal renewedexpansion into the interior. Part of the impetus came from the Lisbon Geographical Society, founded in 1875 by a group of industrialists, scholars, and colonial and military officials. This society stimulated a popular concern for the colonies in Portugal. In reaction to the activities of the society and the growing interest among Europeans in colonial adventure, the Portuguese government allotted large sums for public works in Africa and encouraged a minor revival of missionary work.

An advisory commission to Portugal's Ministry of the Navy and Colonies formed an expedition in the 1870s to link Angola on the Atlantic coast with Mozambique on the Indian Ocean coast. The Portuguese government supported this expedition because it aspired to control a solid strip of territory across the central part of the continent. Nonetheless, Portugal was unable to gain control of the hinterland.

Aware of French and Belgian activities on the lower Congo River, in 1883 the Portuguese occupied Cabinda and Massabi north of the Congo River, towns that Portugal had long claimed. In the same year, Portugal annexed the region of the old Kongo Kingdom. Seeking to uphold these claims against French and Belgian advances in the Congo River Basin, Portugal negotiated a treaty with Britain in 1884; the other European powers, however, rejected it. Portugal's subsequent demands for an international conference on the Congo fell on deaf ears until German chancellor Otto von Bismarck seized on the idea as an opportunity to diminish French and British power.

At the Berlin Conference of 1884, the participants established in principle the limits of Portugal's claims to Angola, and in later years, treaties with the colonial powers that controlled the neighboring territories delineated Angola's boundaries. But because other, more powerful European states of the nineteenth century had explored central Africa, they, not Portugal, determined Angola's boundaries. The west coast territory Portugal acquired included the left bank of the Congo River and the Cabinda enclave, an acquisition whose value to the state was demonstrated in later years by the discovery there of oil. Britain, however, forced Portugal to withdraw from Nyasaland (present-day Malawi) and Rhodesia (present-day Zimbabwe and Zambia).

Portugal and Belgium concluded several agreements between 1891 and 1927, establishing a complex border generally following natural frontiers. Cabinda's boundaries with the French Congo and the Belgian Congo were delimited in 1886 and 1894, respectively, and by the end of the nineteenth century, Portugal had staked out most of its claims in Angola.

As far as Europe was concerned, Angola was in the Portuguese sphere of influence, and its status was not subject to further deliberations. Considering its diminished stature in relation to other European powers, Portugal had done well to hold onto as much territory as it had. But the fact that Angola was recognized as a Portuguese possession did not mean that it was under Portuguese control. The work of conquest took the better part of twenty-five years, and in some remote areas even longer.

Data as of February 1989