Responses
No. I dont know if he's on 30's or 40's but grisha is married with Dina still, he got zeke as his son then +7 years before he was thrown in the island to meet eren's mother, not that long time to pass, he got to the wall before his 50's
If you mean does grisha comes from the very beginning of historia's royalty line, no, he got thrown in the middle, not necessarily middle but enough to make the humans on the wall make their own history
sooooo I was thinking that when Grisha married Eren's Mother, Grisha is wayyyyyy too old like ymir. fck?!