In Game of Thrones, Daenerys Targaryen marries Khal Drogo, a chieftain of the Dothraki people. The marriage is arranged by her brother Viserys and the exiled merchant Illyrio Mopatis as part of a plan to obtain Dothraki military support.
The Dothraki are a nomadic warrior culture from the eastern continent of Essos. They travel in large groups called khalasars, led by a khal; the wife of a khal is known as a khaleesi. Drogo is one of the most powerful khals, and Daenerys becomes his khaleesi after their wedding.
A common mix-up is answering “Khal Drogo,” which is the name of Daenerys’s husband, rather than “Dothraki,” the name of the people he leads. Their relationship also changes Daenerys dramatically: she gradually learns the Dothraki language and customs, gains political authority, and begins developing the leadership identity that later defines her campaign for the Iron Throne.