Edward Kenway joins the group, in a number 5 in the series. Edward Kenway was a pirate in the Caribbean and a member of the Assassin Brotherhood. He is also the grandfather of previous entry Connor Kenway. Hard to imagine, I know.
Edward featured as the protagonist of Assassin's Creed IV: Black Flag, released late last year.
The reference for this was found on his profile page on the AC Wiki.
Edward © Ubisoft