User blog comment:PrincessDaydream77/Series 5!!!/@comment-4892425-20120828014311

Morgana's past would be interesting to explore. I think that's why they brought Uther back from the dead, to put it in context and how does it impact Arthur. Here's how I see it:

When Uther confesses to Gaius about Morgana's true parentage, he says "Arthur must never know". I'm guessing the affair took place during Uther's marriage to Ygraine. Even as queen Ygraine would have been expected to tolerate the presence of his outside child. (Arthur would none too please with that humiliation.)  Insulted by the deed, Goloris and Ygraine's family could join forces and pull Uther down from the throne. It could be the reason why the Pendragons turned to magic to conceive an heir (Arthur): not only to insure the succession, but also make up to Ygraine for cheating and get Goloris and the in-laws off Uther's back. Not acknowlegding Morgana insures that honor has been restored, such as it is.

Goloris must be able to count to nine to realize Morgana's not his child. She was conceived when he was away at war for the Pendragon. Pride and duty forced him to accept the child and not divorce Vivienne; it would raise too many questions. Over time, Goloris grew to love Morgana as his. For Vivienne, she was lonely when she got with Uther, mayble bored with her husband; and she probably thought it was no big deal. Being maitresse en titre, the king's official mistress, is a means for a woman to gain power, prestige and advancement for herself and her family. She was probably disappointed that Uther didn't acknowledge her and Morgana, so she bid her time. When Uther failed to send reinforcements to help Goloris, resulting in Goloris' death, Vivienne saw this as the time that she can finally be with Uther and Morgana would be acknowledged as a princess of the blood royal. Instead, Morgana was taken as a ward and Vivienne was probably killed to silence her. Her family couldn't make a fuss because it was not powerful enough to fight Uther and they may have seen the affair as a disgrace.

Can you imagine Morgana's reaction: her nobly born mother was treated no better than a Back Alley Sally while the daughter of a blacksmith was given the crown matrimonial? Both of Uther's children and a kingdom have been negatively impacted because he couldn't keep it in his codpiece.

My two cents.