Damon Lannister (son of Jason)
|Born||In 244 AC or 245 AC|
|Book||The World of Ice & Fire (mentioned)|
Damon Lannister is a nobleman of House Lannister and the only son of Ser Jason Lannister by his first wife, Alys Stackspear. He is a cousin and half-brother-in-law to Lord Tywin Lannister of Casterly Rock.
In 244 AC, the young Jason Lannister deflowered and impregnated Alys Stackspear, the maiden daughter of Lord Stackspear. Jason was compelled by his brother Lord Tytos Lannister to wed Alys, likely at the behest of Tytos' wife, Lady Jeyne. However, Alys died giving birth to Damon.
It is currently unknown whether Damon is still alive in A Song of Ice and Fire. The fact that Cersei Lannister appointed his son Damion as castellan instead of him might indicate Damon has passed but it is not a definitive argument.
Damon wed Ella Lannister, a distant cousin from House Lannister of Lannisport. He has one son by her, Ser Damion. Through Damion's marriage to Shiera Crakehall, Damon is the grandfather of Lucion and Lanna Lannister.