Prevail Upon Meaning

Example :   Perhaps I can prevail upon him to change his mind.‎1898, Winston Churchill, chapter 10, The Celebrity:  The skipper Mr. Cooke had hired at Far Harbor was a God-fearing man with a luke warm interest in his new billet and employer, and had only been prevailed upon to take charge of the yacht after the offer of an emolument equal to half a year's sea pay of an ensign in the navy.