User blog comment:Cillemaller the Witch/Is Gorlois Morgause´s father?/@comment-84.60.101.82-20120515084142

In case Morgana and Morgause are still half-sisters, Morgause can't be Gorlois' daughter because if she was, Gaius would haver thought that Morgana and Morgause are full sisters when he talked to Uther. At that point of time, nobody knew that Uther Uther was Morgana's father. Since Morgana and Morgause kept calling each other "sister", they must have the same mother.

Vivienne had at least three men in her life. Gorlois, Uther and Morgause's father.