Jon was born in 283 AC, near the end of Robert's Rebellion.[N 1] Jon was named by Lord Eddard Stark. The identity of Jon Snow's mother remains a mystery, and several suggestions have been made by those who know the Starks. Jon is unaware of his mother's identity and Eddard refuses to speak of her. When Eddard returned from the war, he brought the newborn Jon to Winterfell, insisting on raising him with the rest of his family. Jon and his wet nurse had been installed in the castle before the arrival of Eddard's new wife, Catelyn Tully, and his young son and heir, Robb Stark, from Riverrun, which Catelyn did not take well.
Lord Eddard Stark was fiercely protective of Jon and refused to send him away. Jon was raised at Winterfell with his half-siblings, where he was tutored by Maester Luwin, and trained at arms by the master-at-arms, Ser Rodrik Cassel. Jon has trained at swordplay since he was old enough to walk, together with Robb, whom he came to view as his "best friend, rival and constant companion", and later also with Theon Greyjoy, after the latter came to Winterfell following the conclusion of Greyjoy's Rebellion. At some point, Jon learned how to swim in the great moat at Winterfell; he is considered a strong swimmer.
Jon grew close to his true-born siblings, especially Robb and Arya. Due to the fact that they both looked alike, Arya came to believe that she was bastard-born as well and shared with her brother with this fear; Jon reassured his half-sister this was not the case. As a young child[N 2] Jon and Robb built a great mountain of snow on top of a gate, hoping to push in on someone passing by. They were discovered by Mance Rayder, a ranger from the Night's Watch who had accompanied Lord Commander Qorgyle to Winterfell. The ranger promised not to tell anyone, and Jon and Robb succeeded in their ploy, being chased around the yard by Fat Tom, their victim. Jon and Robb would often play a game of sword-play, in which they would pretend to be great heroes (including Florian the Fool, Aemon the Dragonknight, King Daeron I Targaryen, and Ser Ryam Redwyne). Once, when Jon called out that he was "Lord of Winterfell", Robb informed him that it was impossible due to his bastardy, which would become a sore memory for Jon. Another time, Jon covered himself in flour and hid in one of the empty tombs in the crypt of Winterfell, and jumped out to scare Sansa, Arya, and Bran, who had been brought to the crypts by Robb.
Since he was young, Jon's hero was King Daeron, the Young Dragon, who had conquered Dorne at the age of fourteen. Lord Eddard had dreamed about raising new lords and settling them in the abandoned holdfasts in the New Gift, and Jon believes that, had winter come and gone more quickly, he might have been chosen to hold one of the settlements in his father's name.