Complex sentence: Dube was born of royal lineage, actually he was a chief of the Qadi tribe but owing to his father's conversion to early missionary Christianity in pre-republic South Africa he did not rule over his Qadi people.
Split into simpler sentences: Dube was born of royal lineage and was by right a chief of the Qadi tribe. Because of Dube's father's conversion to Christianity by early missionaries in pre-republic South Africa, he did not rule over his Qadi people.