Tristan -- known through medieval legend and Wagnerian opera -- has a slightly wistful, touching air. This, combined with the name's popular "an" ending, makes Tristan very appealing to parents seeking a more original alternative to Christian.
Tristan has been growing in popularity since the 1970s, moving in and out of the Top 100 since 1996, now at Number 97. One influence was the character Tristan Ludlow played by Brad Pitt in the 1994 movie Legends of the Fall, based on a Jim Harrison novel.
Tristan is a dragon-slaying hero of Celtic legend, whose story was incorporated into Malory's Le Morte d'Arthur, in which Tristan is one of the Knights of the Round Table, consumed by his doomed love affair with Queen Isolde. Wagner set the story to music in his opera Tristan und Isolde.
Tristan and its alternate form Tristram have been found in later lit as well. Tristram Shandy is a famous early comic novel by Laurence Sterne (in which the hero's father calls Tristram the worst name in the universe); Tristan is a major character in James Herriott's All Creatures Great and Small, and there is an eponymous novella by Thomas Mann.
Particularly popular in Canada, Tristan was chosen for their sons by Travis Tritt, Wayne Gretzky, Natasha Henstridge and, most recently, by Elsa Pataky and Chris Hemsworth.
Other variants of Tristan include Tristen, Tristin, Triston and Tristian.