User blog comment:Emily Windsnap/How old are the Merlin characters?/@comment-108.40.125.73-20170306195241

Well, we can really only guess that Merlin is around twenty in season 1 when Uther says that it had been 20 years since the Great Dragon had been captured. At the end of season 2 when we meet Merlin's father, we were told that all the dragonlords were gathered to capture the last dragon.