GJ reports that Troilus was in use, at least in Scotland, from early in the 16^th century to the end of the 17^th century, from records in the National Archive of Scotland. The name comes from Homer's Iliad but the meaning is unclear. It's use as a forename in Britain seems to be restricted but it was in use before Shakespeare wrote Troilus and Cressida.

One transcription has the spelling Triolus.