The Andals are one of the three major ethnic groups from which the humans of Westeros descend, the others being the First Men and the Rhoynar. The Andal invasion caused the fall of many of the kingdoms of the First Men which had developed in the wake of the Pact with the children of the forest. The Andals also brought the Faith of the Seven to the Seven Kingdoms. The Lord of the Seven Kingdoms, the king on the Iron Throne, claims to be the King of the Andals, the Rhoynar, and the First Men.
The Dothraki refer to Westeros as Rhaesh Andahli, the land of the Andals. Ser Jorah Mormont, a northman, is called "The Andal" in Essos, even though the Andal influence is less in the north of Westeros.
Andals in Essos
The Andals are said to have originated in the