Menelaus was the King of Sparta, and husband of Helen, who led the Greek forces in the Trojan War. After Helen left him out of love for Paris, Menelaus tried to regain her. Finally, the Greeks win by using a Trojan Horse. Xena rescued Helen, who chose not to return to her husband.
Menelaus is a real historical person who ruled Mycenae before he got married, then ruled Sparta. After the attack with the Trojan Horse, Menelaus was furious that Helen was missing, and blamed Deiphobus; he killed him in rage.