Christian, an Everyman, was a traveller who hailed from an ethereal realm.
He was traveling from the city of Destruction to the Celestial City when he came across Vanity Fair that was founded upon material desires and worldly commerce. Becoming lost in its bawdy, brothel-haunted streets, Christian turned down an alleyway from which he stepped into the London streets in 1678.
Seemingly trapped in our more material, unfamiliar realm, he was confined to a madhouse from which he is later rescued by Prospero and Orlando, and subsequently recruited into Prospero's Men. Christian was very reluctant in allying with the sorcerer Prospero, given his distrust towards Prospero's supposedly "diabolical" inspired magic, but realized that Prospero was his only hope in helping him finding his way back to his world.
In 1683, Prospero's Men travelled to the Blazing World whereupon Christian departs into The Blazing World where he finally returned to his home before waving his friends goodbye.
Christian is from John Bunyan's The Pilgrim's Progress.