They were kings, once, before the Targaryens came. They rode dragons, and united the Seven Kingdoms under their rule, and ruled from the South.

Sixteen years ago there was a war that ousted the Targaryens. They had grown mad, the Mad King was killed, and the Baratheon's then ruled, until lately, when King Joffrey killed Eddard Stark, and the North rose up, and Robb claimed his old Kingship.