Menelaos raged in the insult of the Trojans, then required to respect the oath of former suitors of Helen and turned to Agamemnon. Originally an embassy was sent to Troy to demand the return of Helen and the treasures of the palace in Sparta. Priam, however, wanting to do the favor of his second-son refused to return the stolen and Helen, whom had already greeted as a bride.
Agamemnon and Menelaus knew that the only solution was war. For this purpose they sent embassies to all the Achaean rulers to respect the oath they had given.
Odysseus
The king of Ithaca Odysseus, in the meantime married Penelope and had a son, Telemachus. He pretended to be mad, cultivating his fields with salt. Palamedes, however, put the newborn son of Odysseus to the point where he spent the plow, and then Odysseus stopped and admitted his hypocrisy. Eventually he also was forced to participate in the upcoming war.