The bishop and theologian Fulgentius of Ruspe lived in North Africa at the end of the fifth and at the beginning of the sixth century. At that time, North Africa was ruled by the Homoean Vandals, a fact which influenced both the life and works of Fulgentius. In his theological books he adopted important decisions of the dogma history and markedly distinguished them from the heresies he was confronted with. That is also true for the book “De Trinitate ad Felicem”, in which the author summarizes important Christian beliefs and on which this diploma thesis is based. After a general introduction about the life and works of Fulgentius and after a summary of the most important decisions of the teachings of Trinity and Christology, this thesis aims at answering several questions which are raised in the book “De Trinitate ad Felicem”. Among them are the meaning of the Lords command to baptize all nations for Fulgentius works, the issue of unity and trinity of God and explanations of the three persons of God. Since the influence of Fulgentius idol Augustine on his teachings cannot be denied, it will be discussed in this thesis too. In addition, Fulgentius tries to distinguish his explanations from those of the heretics in the whole book. Therefore, this thesis also illustrates the view of the heretics and how Fulgentius emphasizes the differences between his theology and their heresies in “De Trinitate ad Felicem”. Finally, the reception of Fulgentius works shall be discussed.