I wrote my first historical novel in 2013/14 when I was 22. I'd recently lost my job and I just wanted to occupy myself and do something constructive. I'd always had a passion for history and writing stories so I thought, why not? I randomly picked a period of time I didn't know too much about (Edward II's reign in the 14th century), and began researching like mad. It was a very rewarding experience, and I ended up writing three sequels to it. Unfortunately all four are unpublished (been too scared to approach any publishers, my bad!), and to be fair they all probably need a bit of a polish, however my point is that if you want to write a novel YOU CAN DO IT. Just persevere. At the moment I'm reshaping a couple of novels I wrote in 2015/16 on the reigns of Aethelred, Cnut and Edward the Confessor because I'm a bit more confident about them, and the plan is to get them out there as soon as possible. Just need to hope and pray that someone likes them!
Go and write your novel, now!