Portugal accepted a diplomatic mission from Southern Rhodesia despite objections by Britain, which had required the colony to implement black majority rule as a condition of independence.

The Rhodesian mission in Lisbon, the capital of Portugal, operated from September 1965 to May 1975. It was a diplomatic mission representing Rhodesia, initially as a self-governing colony of Britain and, after the Unilateral Declaration of Independence in November 1965, as an unrecognised state. Rhodesia informed Britain of its intent to open a Lisbon mission headed by an accredited representative, independent from the British Embassy in the city, in June 1965. Whitehall refused to endorse the idea but Rhodesia continued nonetheless, and later that month appointed Harry Reedman to head the mission. The British government attempted unsuccessfully to block this unilateral act—Rhodesia's first—for some months afterwards.