Jon Snow

Jon Snow is the son of Lady Lyanna Stark and Rhaegar Targaryen, the Prince of Dragonstone. From infancy, Jon is presented as the bastard son of Lord Eddard Stark, Lyanna's brother, and raised by Eddard alongside his lawful children at Winterfell but his true parentage is kept secret from everyone, including Jon himself. In order to escape his bastard status, Jon joins the Night's Watch and is eventually chosen as Lord Commander. However, his decision to allow thousands of Free Folk safe passage through the Wall alienates many of his black brothers, culminating in a mutiny where Jon is killed but later revived by Melisandre. Freed from his Night's Watch vows, Jon executes the mutineers and joins his cousin, Sansa Stark, in building an army to retake Winterfell from House Bolton. After securing help from a few other Northern Houses and the Vale of Arryn, they successfully retake the castle from Ramsay Bolton, restoring House Stark's dominion over the North with Jon being declared the new King in the North by the Northern Lords.

Eighteen years before the War of the Five Kings, Rhaegar Targaryen allegedly abducted Lyanna Stark of Winterfell in a scandal that would lead to the outbreak of Robert's Rebellion. Rhaegar would eventually return to fight in the war, but not before leaving Lyanna behind at the Tower of Joy, guarded by Lord Commander Gerold Hightower and Ser Arthur Dayne of the Kingsguard. Lord Eddard Stark, Lyanna's brother, rode to war along with her betrothed, Robert Baratheon, to rescue his sister and avenge the deaths of their father and brother on the orders of Rhaegar's father, Aerys II, the Mad King. Robert would ultimately kill Rhaegar at the Battle of the Trident, effectively ensuring their victory in the war. After the Sack of King's Landing, Ned continued south in search of his sister, and ultimately found her at the Tower of Joy, in the Red Mountains at the border of Dorne. Ned and his companions engaged in a final fierce melee with the remaining Targaryen Kingsguard, that resulted in the deaths of all combatants save Ned himself and Howland Reed. After defeating the last of the Kingsguard, Ned rushed into the tower to save his sister - only to find Lyanna dying from childbirth, having just given birth to Rhaegar's own son. Desperate to protect the life of her newborn child, a fading Lyanna pleaded with Ned to promise her that he would keep her son safe, and his true heritage hidden from Robert as he had been Rhaegar's most bitter enemy. Furthermore, the boy's existence was a potential threat to Robert's claim to the Iron Throne after the deaths of Rhaegar's other children, Rhaenys and Aegon, by his wife Elia Martell, who also perished, during the Sack of King's Landing. In accordance with her last wish, Ned resolved to pass Lyanna's son off as his own bastard and raise him in his home castle - a great blow to his honor as he knew that his decision would shame both himself and his lady wife, Catelyn Tully. Ned decided not to use his nephew's birth name, which Lyanna revealed to him in her final moments - apparently because it was a Targaryen-style name which would have given away his real parentage. Instead, he chose to give the baby the name "Jon" after his great friend and mentor Jon Arryn, Lord of the Vale, whom he loved like a second father. The boy also grew up using the surname "Snow", as is customary for acknowledged bastards in the North. In truth, it is unclear if "Jon" actually is a bastard at all. Rhaegar was already married to Elia at the time of the rebellion but the Targaryens have been known to enter into polygamous marriages in the past - leaving open the possibility that he might have used that precedent to wed Lyanna. On the other hand, it is also unknown if Lyanna eloped with Rhaegar or was in fact simply raped by him as King Robert claimed - though in this case, Rhaegar could have forced Lyanna to marry him.