Menelaus
Menelaus was one of the sons of Atreus. He and his brother Agamemnon were banished from Mycenae after their father was killed by Aegisthus and Thyestes took the throne.
Menelaus sought the hand of Helen, who was the most beautiful woman in the world, as well as immortal (her true father was Zeus in the form of a swan). A number of other suitors sought her hand, and to prevent open warfare from breaking out, her mortal father required them all to agree to defend the winning suitor, and then had them draw straws. Menelaus won the draw and married Helen while Agamemnon married her mortal half-sister, Clytemnestra.
The two brothers thereafter returned to Mycenae and drove Thyestes away. The brothers got along remarkably well, especially considering that they belonged to the House of Atreus, and they apparently amicably agreed that Agamemnon would be king of Mycenae while Menelaus became king of Sparta after Helen's mortal father died without male heirs.
Unfortunately, Aphrodite, the Goddess of Love, had promised Paris the hand of the most beautiful woman in the world, as a result of the Judgment of Paris. While Menelaus was away, Aphrodite induced Helen to run away to Troy with Paris, precipitating the Trojan War.
After the Greeks prevailed in the Trojan War, Menelaus took Helen back and apparently lived out his life in relative peace, unlike his brother Agamemnon.