Rosamund Lannister is the fourth child of Lord Tyland Lannister and his wife Serra Swyft. She is a thrall of House Botley, and has assumed the name Runa. She is presumed dead by the rest of her family, having been lost during a storm after the Battle of the Lions began.
Rosamund lacks traditional Lannister beauty. She is blue-eyed and has pale hair. She is also short, and dresses in finery when it is afforded her.
Rosamund was born in 183 AC. During the Battle of Lions, she was abducted by Lord Crakehall, and rescued by Ythan Dayne. Afterward, she developed the persona of Runa and was sent to King's Landing to become Princee Helaena's Lady in Waiting.