Final answer:
Odysseus kills Antinous first to send a powerful message to the other suitors, assert his authority, and avenge the mistreatment of his family and home.
Step-by-step explanation:
In the epic poem 'The Odyssey' by Homer, Odysseus decides to kill Antinous first among the suitors for several reasons. Antinous is depicted as the cruelest and most arrogant of the suitors; he not only leads the campaign to marry Penelope and usurp Odysseus's throne but also mistreats and mocks Odysseus in disguise. By striking down Antinous first, Odysseus is sending a powerful message to the others and asserting his royal authority. Additionally, Antinous posed an immediate threat as he was about to drink from a cup, unwitting to the danger he was in, symbolizing the ease with which he has been living off Odysseus's wealth. His sudden and shocking death sets the tone for the ultimate reckoning that follows.