User blog comment:Emily Windsnap/How old are the Merlin characters?/@comment-1881345-20120504052724

At the beginning of the series, 20 years without magic is celebrated in Camelot. Arthur's conception, which resulted in Igraine's death, caused the Great Purge, led by Uther. Because of this we can assume that Arthur is about 20 years old in S1. I read somewhere that the legal age in Camelot is 21, and in S4 they change "boy" to "man" in the intro, implying that Merlin has turned 21. And in the the episode "Excalibur" from S1, it starts off with Arthur's coming-of-age ceremony, so I think he turns 21 in that episode. I think Arthur is about 2 years older than Merlin, so in S1 Merlin's about 18-19 and Arthur's 20-21. As for Morgana, however...I'm not really sure. I know she is conceived by adultery between Vivenne and Uther, but I don't know if this was before or after Uther married and conceived with Igraine. I'd say Morgana is around Arthur's age though, if not, slight older, around the 21-22 range in S1. As for Gwen...gah I don't know. Nothing's given about her background but I assume that she's around 23, because Angel is the oldest out of the actors xD All in all, I think the characters are about 21-25 in S4. And given the fact that years have passed by in S5, the characters will probably be at the age the actors are (mid to late twenties).

Nimueh has been around for a while, she did help Uther and Igraine to conceive Arthur, and I think she was an adult by then so she must be pretty old, and her young appearance is just an illusion. Morgause, I think, is older by Morgana by a couple of years. Her father is presumably Gorlois so this was probably before Vivenne had an affair with Uther (as the only known other child of her's is Morgana). Morgause was smuggled out of Camelot as a baby during the Great Purge, though, so maybe she's the same age as Morgana. I don't know why though, because Emilia Fox looks older than Katie McGrath and Bradley James xD

But yeah, that's what I think! xD