The Portuguese-Algerian War was a period of diplomatic crisis between Algeria and Portugal, It was marked mostly by a series of naval battles that happened between 1790 and 1813, until they signed a friendship treaty in 1813, ending all hostilities.

There were naval battles between Algerian and Portuguese sailors from the 17th century, particularly in the vicinity of the Strait of Gibraltar and the eastern part of the Atlantic Ocean.

[8][9] In 1807, following a successful mission, Rais Hamidou obtained a Portuguese slave trophy, which he later sold in Morocco for 11,787 Francs.

[8][10] In 1810, an Algerian naval force captures 3 Portuguese ships full of tobacco, The commander returned two of the boats and kept the third one for himself.

[1] On June 14, 1813, Portugal was compelled to sign a treaty with Algiers, agreeing to pay a total of 1,027,000 francs, which included 690,000 for war reparations and 337,000 for the return of 615 Portuguese prisoners, The treaty was signed between Dey Hadj Ali and regent Prince John IV, In addition to this, Portugal would have to pay 16,000 worth of gifts to the Pasha of Algiers.