User blog comment:GianG/Merlin characters ages/@comment-5674726-20141103011022/@comment-5674726-20141103190146

"Yes, I guess you are right about Gwen, I didn't think to this. However, I think that Gwen should be younger than Morgana (even though she seems older), because in Series 1 she was a young maid to Morgana."

I can't recall her being described as a "young" maid in any episode. I'd have said that she was the oldest of the younger generation of characters - which would fit with Angel Coulby being three years older than Bradley James, who is next in age - based on her behaviour. She is the most level-headed and mature of the four.

"Morgana should be older than Artù, because of her behavior in Series 1 and 2 and especially because she claims to be the rightfully queen."

I think that Morgana's mental state in Season Four and especially in Season Five makes it very hard to determine why she believes that she is the rightful heir to the throne. As a female child born out of wedlock, she would not be considered the rightful heir to the throne over a male child born in wedlock, regardless of their ages. My guess would be that a combination of desire for the throne, having conquered Camelot in the past, unwillingness to give up her quest to be Queen of Camelot after Morgause gave her life to the cause, and her emotional instability led her to conclude that she was the rightful Queen. Age may or may not be a factor.

(There was also an interesting theory in a blog a good while back that due to the circumstances of his birth, Arthur is not actually Uther's biological child and that Morgana could see the throne as hers as she is the only surviving heir of Uther's bloodline.)