Britain's relationship with Morocco was increasingly influenced by the growing rivalry between the great powers. With the establishment of the French Protectorate in the early 20th century, British interests became largely limited to Tangier, where Britain played an important role in the international administration of the city. A substantial British community grew up there, and Tangier retained a British flavour for many years afterwards. During the Second World War, Britain and the United States were anxious to prevent Morocco falling under the control of the Axis powers. Britain's Prime Minister Winston Churchill and President Roosevelt of the United States met King Mohammed V of Morocco at Casablanca in 1943, at one of the most important Allied conferences of the war.

Since Morocco's independence in 1956, British-Moroccan relations have once again grown steadily in importance. Her Majesty Queen Elizabeth II visited Morocco in October 1980, and His late Majesty King Hassan II paid a return visit to London in July 1987. His Royal Highness Prince Charles has visited Morocco on several occasions, most recently in 1999, to attend the funeral of the late King.