Achilles brought 50 ships to Troy.
The figure comes from Homer’s Catalogue of Ships in Iliad Book 2, which lists the contingents that sailed against Troy. Achilles commands the Myrmidons, along with the Hellenes and Achaeans associated with Phthia and neighboring regions. Their contingent is recorded as 50 ships.
The number refers to ships, not individual warriors. The poem also gives a troop figure of 50 men per ship for Achilles’ contingent, producing a traditional total of 2,500 men. These figures belong to the epic catalogue, a poetic inventory of the Greek forces rather than a modern logistical record.
Achilles’ ships are especially important later in the poem. When Achilles withdraws from the fighting after his quarrel with Agamemnon, his Myrmidons remain by the ships. Patroclus eventually leads them into battle wearing Achilles’ armor, and Hector kills him. Achilles then returns to combat after receiving the replacement armor forged by Hephaestus.
The 50 ships should not be confused with the much larger total assigned to the entire Achaean army.