Lann

Lann, known as Lann the Clever, was a legendary trickster of the Age of Heroes. House Lannister boasts descent to him through the female line.

According to legend, Lann the Clever swindled Casterly Rock from its previous rulers, House Casterly, using nothing but his wits.

In the books
In the A Song of Ice and Fire books, Lann the Clever is the founder of House Lannister and a popular character among singers and storytellers. One of the stories narrates how he stole gold from the sun to brighten his hair.

Although the Lannisters are of predominantly Andal blood, Lann was allegedly one of the First Men. His descendants through the female line married into the invading Andal family which conquered Casterly Rock and gave them his name.