Romero sometimes played the leading man, for example in Allan Dwan's "15 Maiden Lane" (1936) opposite Claire Trevor, as well as winning the key role of the Doc Holliday character (with name changed to "Doc Halliday") in Dwan's Wyatt Earp saga "Frontier Marshal" three years later. 20th Century Fox, along with mogul Darryl Zanuck, personally selected Romero to co-star with Tyrone Power in the Technicolor historical epic "Captain from Castile" (1947), directed by Henry King. While Power played a fictionalized character, Romero played Hernán Cortés, a historical conquistador in Spain's conquest of the Americas.