The first major event is Jason losing his claim to the throne due to his Uncle coming this is shown when the text says "Phrixus had an uncle who was by rights a king in Greece, but had had his kingdom taken away from him by his nephew, a man named Pelias. The King's young son, Jason, the rightful heir to the kingdom," (Hamilton 2) which shows Jasons true blood.
The second would be Jason growing up and coming back to reclaim the throne which was foreshadowed when the oracle said "he would die at the hands of kinsmen, and that he should beware of anyone whom he saw shod with only a single sandal." (Hamilton 2) which is referring to Jason himself.
Another important event would be when Hera chooses to help Jason in order to spite the king. Her support of Jason is shown when the text says "Hera was helping Jason, and it was she who kindled in each one the desire not to be left behind nursing a life without peril by his mother's side," (Hamilton 3) which is due to multiple reasons.
The next important event would be Hercules ran off in search of his friend. This important because the text says "Hedid not come back, and finally the ship had to sail without him." (Hamilton 4) because this means he could have died.
My fifth important even is the arrival of the old man because the text says " a lonely and wretched old man, to whom Apollo, the truth-teller, had given the gift of prophecy." which shows by itself the importance of the man.
The sixth event is when the Argonauts come across man who is in need of help. The text states that "Whenever he was about to dine, the Harpies who were called "the hounds of Zeus" swooped down and defiled the food," (Hamilton 4) which shows how dire the situation is.