what did Bassanio do before he went to Portia to ask her hand in marriage?

Bassanio, before heading for asking Lady Portia's hand in
marriage,helped the escapade of the lovers Jessica (Shylock's daughter) and Lorentzo
(one of previous soldiers of Shylock). He helped them to escape from Shylock and Venice
by sailing them in one of Antonio's ship. After arriving in Belmont, he heads for wooing
Lady Portia which he is able to do successfully by choosing the right casket. He chose
the Lead Casket containig Lady Portia's portrait and thus, won her hand for
marriage.