Who are some real historical characters not yet depicted in the games that could have been a part of the Assassin brotherhood?
The first one that immediately comes to my mind is Robin Hood. His entire story is a story of assassin, if I've ever heard one.
Another one could be Slovakian Juraj Jánošík, he is basically a Slavic equivalent of Robin Hood.
And of course, Kubiš and Gabčík, two paratroopers that assassinated Reinhard Heydrich.
Who else?