9 main games? Does Rogue not really count as a main title? I guess it is kind of a side story but I feel it has enough content to count towards the core storyline, especially with how it ties to Unity at the end.

That’s 9 main games after the release of the first Assassin’s Creed game:

1. Assassin’s Creed II
2. Assassin’s Creed Brotherhood
3. Assassin’s Creed Revelations
4. Assassin’s Creed III
5. Assassin’s Creed IV Black Flag
6. Assassin’s Creed Unity
7. Assassin’s Creed Rogue
8. Assassin’s Creed Syndicate
9. Assassin’s Creed Origins