Anglo-Portuguese Treaty of 1891

The Anglo-Portuguese Treaty of 1891 was an agreement between the United Kingdom of Great Britain and Ireland and Portugal which fixed the boundaries between the British Central Africa Protectorate, (now Malawi), and the territories administered by the British South Africa Company in Mashonaland and Matabeleland, (now parts of Zimbabwe), and North-Western Rhodesia (now part of Zambia) and Portuguese Mozambique and also between the British South Africa Company administered territories of North-Eastern Rhodesia (now in Zambia), and Portuguese Angola. This treaty brought to an end over 20 years of increasing disagreement over conflicting territorial claims in the eastern part of Central Africa, where Portugal has long-standing claims based on prior discovery and exploration but where British citizens set up missions and embryonic trading concerns in the Shire Highlands in what is now Malawi from the 1860s. These disagreements were increased in the 1870s and 1880s, firstly by a dispute over a British claim to part of Delagoa Bay and by the failure of bi-lateral negotiations between the two countries over the boundaries of Portuguese territories and secondly as a result of the Berlin Conference of 1884–85, which set-out the doctrine of effective occupation. After the Berlin Conference, Portugal tried to establish a zone of effective occupation linking its colonies in Angola and Mozambique through expeditions making treaties that would establish protectorates over local peoples and obtaining recognition from other European powers. The relative success of these Portuguese efforts alarmed the British government of Lord Salisbury, which was also under pressure from missionaries in the Shire Highlands, and also Cecil Rhodes, who founded the British South Africa Company in 1888 with the aim of controlling as much of south-central Africa as it could. For these reasons, and in response to a minor armed conflict in the Shire Highlands, Lord Salisbury issued the 1890 British Ultimatum which required Portugal to evacuate the areas in dispute. Lord Salisbury refused the Portuguese request for arbitration and, after an abortive attempt to fix the boundaries of their respective territories in 1890, the Anglo-Portuguese Treaty of 1891 was accepted by Portugal under duress.

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