In Celtic myth, the hero known for his tragic love story with Deirdre is Naoise. Their tale is one of deep love, tragedy, and fate, often referred to as "The Tragedy of Deirdre." Deirdre, prophesied to bring disaster to her clan, falls hopelessly in love with Naoise. Their romance stirs intense conflict with her family, leading to a sequence of heartbreak and tragedy. The tale exemplifies themes of love, betrayal, and the consequences of destiny.