Why does Odysseus kill Antinous First?

Our answer below is sourced directly from the text of The Odyssey, and includes key passages from the text to support it.

Odysseus kills Antinous first because he had shown disrespect to Odysseus, had threatened him with violence, and had plotted to kill his son. Furthermore, Antinous had taunted Odysseus by offering him a chance to fight Irus, and had promised to send him to the mainland to face the cruel King Echetus if he lost. Antinous had also insulted Odysseus by refusing to give him anything when he begged for help, despite the fact that he had been generous to other beggars in the past. He had also plotted to kill Telemachus, despite the fact that Ulysses had once saved his father from the same fate. Eurymachus, the leader of the suitors, had also acknowledged that Antinous was the head and front of the offending and deserved the death he had received. Penelope had also expressed her hatred for Antinous, wishing that Apollo would strike him down for his mistreatment of the beggar. Odysseus was determined to take revenge and make sure that justice was served.

Here are the top passages from The Odyssey related to the question:

Then Antinous said, “What god can have sent such a pestilence to plague us during our dinner? Get out, into the open part of the court, or I will give you Egypt and Cyprus over again for your insolence and importunity; you have begged of all the others, and they have given you lavishly, for they have abundance round them, and it is easy to be free with other people’s property when there is plenty of it.” On this Ulysses began to move off, and said, “Your looks, my fine sir, are better than your breeding; if you were in your own house you would not spare a poor man so much as a pinch of salt, for though you are in another man’s, and surrounded with abundance, you cannot find it in you to give him even a piece of bread.”

On this he aimed a deadly arrow at Antinous, who was about to take up a two-handled gold cup to drink his wine and already had it in his hands. He had no thought of death—who amongst all the revellers would think that one man, however brave, would stand alone among so many and kill him? The arrow struck Antinous in the throat, and the point went clean through his neck, so that he fell over and the cup dropped from his hand, while a thick stream of blood gushed from his nostrils. He kicked the table from him and upset the things on it, so that the bread and roasted meats were all soiled as they fell over on to the ground.[166] The suitors were in an uproar when they saw that a man had been hit; they sprang in dismay one and all of them from their seats and looked everywhere towards the walls, but there was neither shield nor spear, and they rebuked Ulysses very angrily. “Stranger,” said they, “you shall pay for shooting people in this way: you shall see no other contest; you are a doomed man; he whom you have slain was the foremost youth in Ithaca, and the vultures shall devour you for having killed him.”