Burn! (1970) on Netflix

Sir William Walker (Marlon Brando) is called to the island of Queimada in the Antilles to foment a rebellion against Portuguese rule, to benefit British sugar traders. He singles out a porter named José Dolores (Evaristo Márquez) and tries to insult and humiliate him to goad him into betraying some rebellious spirit. When this eventually works, Walker beings to fashion Delores into a revolutionary leader. At the same time Walker meets with the colonial leaders (ethnic Portuguese) and encourages them to lead the revolution, lest the slaves lead the revolution on their own, which would threaten all white infrastructure, and lives, on the island. The revolution succeeds, the Portuguese are expelled, subtle power struggles ensue between the former colonials and the freed black slaves, and the future of sugar exports is uncertain. Having completed his mission, Walker returns to England.