User blog comment:OneofthePendragon94/The age of Merlin, Arthur, Morgana and Gwen./@comment-82.161.239.52-20200609161212

In season 4 they changed it from young boy to young man, so I thought Merlin was 21 in season 4,  but between season 3 and 4 there's a one-year gap so he could also be 22 in season 4 and he was 21 in the gap, so in season 3 he must've been 19 or 20 years old. Between season 2 and 3 there's also a one-year gap, so between those two season Merlin must be 18 or 19 years old, so in season 2 he's 17 or 18. I don't know how many years there are between season 1 and 2 so in season 1 I think he could be 16, 17 or 18. ​​​​My personal guess: Season 1:  16 Gap:  17 Season 2: 18 Gap:  19 Season 3: 20 Gap: 21 Season 4: 22 Gap of 3 years: 23, 24, 25 Season 5: 26

Arthur is pretty obvious as he became crown prince in season 1, he must've been 20 in the beginning of season 1. My personal guess again: Season 1: 20 Gap: 21 Season 2: 22 Gap: 23 Season 3: 24 Gap: 25 Season 4: 26 Gap of 3 years: 27, 28, 29 Season 5: 30

I think Morgana is older than Arthur, I don't know how many years, I think 2. My personal guess about Morgana: Season 1: 22 Gap: 23 Season 2: 24 Gap: 25 Season 3: 26 Gap: 27 Season 4: 28 Gap of 3 years: 29, 30, 31 Season 5: 32

I literally have no idea about Gwen, I think she has the same age as Merlin or is one year older. My personal guess again, but about Gwen: ​​Season 1: 17 Gap: 18 Season 2: 19 Gap: 20 Season 3: 21 Gap: 22 Season 4: 23 Gap of 3 years: 24, 25, 26 Season 5: 27

So yes, I think Merlin is the youngest of the four, after that Gwen, than Arthur and Morgana is the oldest.

This is just what I think, I've got very little proof and Gwen was all a guess, I don't know where you can find how old she is.

Thank you if you have read this all.