England have searched unsuccessfully for a player who can keep wicket adequately and score runs consistently since Stewart quit after scoring 8,463 test runs at an average of 39.54.
This year they discarded Geraint Jones and Chris Read after the 5-0 Ashes loss to Australia while 36-year-old Paul Nixon, who enjoyed some success with the bat at the World Cup, was apparently viewed as a stopgap measure only.
For Thursday's first test against West Indies, England have turned to 25-year-old Prior, who was born in Johannesburg to an English father and South African mother.
Prior, who has played under new England coach Peter Moores for both Sussex and England A, averages just over 38 in first class cricket. He also played 12 one-day internationals in Zimbabwe, Pakistan and India, only once as a keeper.
"At the end of last summer my goal was this first test match," Prior told a news conference on Tuesday. "I just thought realistically let's try and really set a goal.
"All you can do is concentrate on your own game and try and pinpoint areas where I needed to improve and show the selectors that I'm the guy for the job.
"I like to think it is performance that got me there, I average nearly 40 in first class cricket I had a great winter in Bangladesh (with England A).
"Everyone has stated that runs are important to be a wicketkeeper. If your wicketkeeper can score hundreds for you in test cricket it makes a huge difference."
Prior, who took up wicketkeeping when the regular Sussex under-13 keeper failed to turn up for a game, said he enjoyed keeping.
"I love it as much as my batting," he said. "Not only the keeping but the role of a keeper, the man in the engine room."
England have also named Owais Shah in their 12 for the first time since he scored 88 and 38 run out on his England debut in India last year.
Shah, who may still miss out on a second cap if England decide to play five bowlers, said he had been told he had to make way after the tour for Marcus Trescothick, who had left India early because of stress.
"Of course I felt down, you go through ups and downs generally in your career anyway. But you can't stay down for too long otherwise you just go round moping," he told a news conference.
"You have got to see the problem, address it and then you move forward. I was just thinking try and get some runs and just keep knocking on the door, it's as simple as that."
