Menelaus, son of Atreus, is the brother of Agamemnon. He is also the husband of Helen and, therefore, when Paris/Alexander abducts her, Menelaus wants to recover his wife, so he enlists the aid of his brother, Agamemnon, and many other noble Greeks.
In Homer's Iliad, Menelaus makes a major appearance in the third book, as he has a one-on-one duel with Paris. Menelaus would have killed Paris if goddess Aphrodite had not rescued him. Immediately after Paris is rescued, Menelaus is wounded by the Trojan Pandarus (Iliad 4).
Menelaus recovers, though, and returns to the fighting in Iliad 11, as he and Ajax rescue Odysseus when he finds himself cut off from the rest of his comrades. In Iliad 13, Menelaus appears again as he kills the Trojan Peisander.
We find Menelaus again in Iliad 17, when he kills the Trojan Euphorbas and then, accompanied by Ajax, tries to protect and recover the body of Patroclus. Throughout that book, Menelaus continues to protect Patroclus and eventually sends Antilochus to tell Achilles of his friend's death.
In Iliad 23, Menalaus barely loses the chariot race during the funeral games for Patroclus.
Elsewhere in the saga of the Trojan War, we hear that Menelaus was one of the Greek warriors hidden inside the wooden horse and that he participated in the final destruction of Troy. After the war, Menelaus was reunited with his wife Helen and eventually they made it back to their native land of Sparta. In the fourth book of Homer's Odyssey, we find them at home and living a seemingly happy existence.