Christian was born in the late 1800's in England, much of his early life is unknown. At some point his relationship with his father went sour, likely due to his father believing art is evil and love is a waste of time and telling his son he would waste his life away. Eventually Christian heard of the Bohemian Revolution going on in Paris, France and so, sick of his narrow minded father, Christian left for Paris to become a writer.
He joins the production Spectacular Spectacular, and ends up meeting Satine at the Moulin Rouge (Diamonds are a Girl's Best Friend) where she mistakes him for the Duke, who she is to seduce into funding the nightclub. We also learn that Satine is dying of consumption, or Tuberculosis.
They meet in the Elephant, where Christian tells her of his writing abilities. Satine misinterprets this as a turn-on, and continues attempting to seduce the visibly uncomfortable Christian. He sings, finally catching her attention. She realizes he is not the Duke not soon after, and she tells him he needs to leave. The Duke appears, and Satine distracts him while trying to allow Christian to escape.