LAGOS, Nigeria — At 16, Isaac Fadoyebo ran away from his home in southwest Nigeria and signed up to fight for Britain in World War II, a decision made from youthful exuberance that saw him sent to Burma to fight and nearly die.

Courage and luck kept him alive behind enemy lines as local farmers protected him for months until the British broke through and found him. When he returned home to Nigeria, his story and those of his fellow veterans largely fell away from the public’s mind as independence swept through the country and a devastating civil war and political unrest later followed.

Fadoyebo, who died in November at the age of 86, represents one of the last so-called “Burma Boys” in West and East Africa. On Thursday, his family and friends gathered for a final worship service and celebration of his life, as new attention has been paid to his sacrifices and those of other Africans drawn into the fighting....