Question: Who Were the Argonauts?
Answer: The Argonauts of Greek mythology are the people who sailed on a ship called the Argo -- named after its builder, Argus. The crew were named for the boat plus a word for sailors (naut-) -- Argonauts.
Named for the argonauts, Apollonius' poem is called the Argonautica.
(ll. 1-4) Beginning with thee, O Phoebus, I will recount the famous deeds of men of old, who, at the behest of King Pelias, down through the mouth of Pontus and between the Cyanean rocks, sped well-benched Argo in quest of the golden fleece.
King Pelias in Thessaly was (usually counted) a usurper who sent the rightful claimant to the throne, Jason, on a quest. Pelias intended it as a suicide mission, since it was to bring back the well-guarded and priceless Golden Fleece from Colchis on the Black Sea (Pontus).
Jason gathered together the glory-seeking heroes and demigods of the time and packed them on board a special boat called the Argo. As stated at the start, these sailor-adventurers were the Argonauts. They engaged in many adventures on their way to Colchis, so several of the men enhanced their heroic status. Some of the creatures they encountered appear in other stories of the Greek heroes, making the story of the Argonauts a central myth.
The list of the Argonauts varies with the writer. Since I've already mentioned Apollonius of Rhodes, his list includes such illuminaries as Hercules (Heracles), Hylas, the Dioscuri (Castor and Pollux), Orpheus, and Laocoon. Apollonius is our most complete version of the Argonauts, but the Argonauts are mentioned throughout ancient classical literature. Apollodorus wrote a different list, which includes the heroine Atalanta, whom Jason denied in Apollonius' version, but who is included by Diodorus Siculus, and Theseus, who was previously engaged in Apollonius' version. Timeless Myths says the earliest version of the Argonauts comes from Pindar Pythian Ode IV, whose list of Argonauts is: