Answered by Barbara Bair:
Marcus Garvey and Haile Selassie were not enemies; nor were they friends. Garvey was initially a very strong supporter of Selassie as hostilities between Italian and Ethiopian troops began at Wal Wal in December 1934, and events began to unfolded leading into the Italo-Ethiopian War.
Garvey moved from Jamaica to London as Mussolini was increasing his belligerence against Selassie's rule. The UNIA leader often spoke supportively about Selassie and decried the Italian invasion of Ethiopia from Speaker's Corner in Hyde Park in London, defending the black nation's sovereignty rights and denouncing Mussolini's aggression. He used the pages of his _Black Man_ magazine to discuss the Italo-Ethiopian situation. But after Italian troops invaded Ethiopia in October of 1935 and Selassie was forced into exile in May, Garvey became increasingly critical of the Ethiopian leader.
When Selassie arrived in London, on his way to attempt further negotiations for help (which would not be forthcoming) from the League of Nations, he spurned Garvey along with other black activists then living in Britain. Garvey felt this rejection keenly, and at the same time he was attracted to the power dynamics at work in the rising fascism of Mussolini and Hitler. While African Americans in the United States, including Garveyites led by UNIA New York officer A. L. King in Harlem, rallied to the Ethiopian cause, Garvey began to blast Haile Selassie for his weakness in his _Black Man_ editorials, criticize him for his lack of identification with blacks and for turning to white officials (who would fail him) for help, and, at the same time, praised Mussolini for his forcefulness and his manhood.
Marcus Garvey was heckled off the platform in Hyde Park by African students who were so enraged by his criticism of Haile Selassie. Despite the actual differences the two men experienced, they have been lauded together and twinned spiritually in much of black popular culture and faith, and exist in important relationship to one another in Rastafarian belief, in the messages of reggae music, and in many other ways.