the motives which drove Jason to marry twice.

I think Jason and Pericles had many similar motives that drove them to marry twice and on the first place I think both Jason and Pericles married their first wives just to return them favors. Jason was born and his father was killed so he was exiled and King Pelias took over. When Jason grew up and returned Iolcus, he did a good deed--he carried an old woman over a stream. This bag lady turned out to be Hera (Jason is the beloved of Hera) and apparently Jason tripped and lost a sandal in the stream. At any rate, he comes to the court of King Pelias in Iolcus in northeastern Greece and Pelias asked Jason that he’d be a king if he brings him the fleece. So, in order to follow Pelias’ orders and to be wanted to be a king, Jason gathered all of the heroes in Greece and builds a sheep and began to march towards fleece and on his way he meets Medea.

Medea helps him regain his throne by having the daughters of King Pelias of Iolcus in northeastern Greece kill their father. She chops...