Balon Swann

Balon Swann is an unseen character mentioned in the second season. Ser Balon Swann is a knight of some renown.

Season 2
Ser Alton Lannister recalls that Ser Jaime Lannister defeated Ser Balon in the tournament at Willem Frey's wedding.

In the books
In the A Song of Ice and Fire novels Ser Balon is a highly regarded knight. He is the second son of Lord Gulian Swann, the head of House Swann. He is good with a lance, better with a morningstar and exceptional with a bow. He replaces Ser Preston Greenfield in the Kingsguard following his death in A Clash of Kings. Ser Preston has not been firmly established in the series (although all of the Kingsguard apart from Jaime have appeared together) so it is unclear if Ser Balon has replaced him.