Black actors in "Game of Thrones"?

How many black actors appear in the TV Series Game of Thrones?

I know that there is one in Dorne (The guard of Doran Martell - Areo Hotah) and another in Qarth (Xaro Xhoan Daxos).

How many more appear?

EDIT:
I found one more: Salladhor Saan
System Down found: The priest of the Many Faced God (pre-transformation)