Yup I heard about this... By the way, I think it's great if you played the first five games in order:

• Assassin's Creed
• Assassin's Creed II
• Assassin's Creed: Brotherhood
• Assassin's Creed: Revelations
• Assassin's Creed III

Those tell Desmond's story and it's very interesting to play it in order... All the games after that aren't played by desmond. But after playing III I suggest playing those:

• Assassin's Creed IV: Black Flag <-(You Played it)
• Assassin's Creed: Rouge

Rouge starts sometime after Black Flag and ends in the middle of III timeline. The battle between Assassins and Templars is very interesting!! I didn't play Unity and the ones after it yet.... But I have hope in Origins.