Jon Snow was born Aegon Targaryen. He is the kid of Rhaegar Targaryen (the late Prince of dragon rock) as well as Lyanna Stark. From his birth, he exists as Lord Eddard Stark's (Lyanna's brother) bastard child. He was increased by Eddard with his legit youngsters at Winterfell. His real parentage was maintained a key from him for many years. His desire to escape the tag of a bastard makes him join the Night's watch where is ultimately selected to be the Lord Leader.
He in the future murdered in a mutiny, where he is reanimated by Melisandre who is the red priestess. This released him from his evening watch vows and afterwards Jon joins his cousin Sansa Stark to build an army together and also reclaim Winterfell from your home Bolton, hence restoring the Ascendancy of Stark over t