Drogo

Khal Drogo is a character in Game of Thrones. He is played by Jason Momoa and appears in the first episode.

Drogo is a khal or warlord of the Dothraki, the famed nomadic horse-lords of the eastern continent. The Dothraki are fierce warriors, skilled in battle, unrelenting in combat and known for savagery towards non-Dothraki, although amongst themselves and with certain respected outsiders they have their own code of honour, albeit still a harsh and unforgiving one. Drogo is very young to have his own khalasar, particulary such a large one. Drogo's pride is such that he desires the most beautiful and exotic woman in the world to become his khaleesior wife, and to this end has enlisted the help of Magister Illyrio Mopatis of Pentos in finding such a woman, and so, ends up marrying Daenerys Targaryen.

In the books
In the Song of Ice and Fire novels, Drogo commands forty thousand Dothraki warriors and is a skilled and respected warleader.