Drs Peter Sowerby (81) and David Stables were working at Egton Surgery in the 1980s when Dr Sowerby devised a system for computerising patient records.

The pair wrote the software together and trialled it at the surgery, founding the company Egton Medical Information Systems (EMIS).

Today, the system is used by nearly 60% of GP practices in the country and has 34 million records on file, with the company's turnover last year reaching £58m.

It is a far cry from the early days in Egton when Dr Stables (51) joined the practice.

"I came along in the late 1980s but Peter had been the family GP there for over 25 years," said Dr Stables.

"He was way ahead of his time and recognised that computerised records would be the future and when I came on board we set about writing the software.

"Originally we just used it for the Egton surgery but then people started finding out about it and we got an order for one, then two, then four, then 10 and it just grew from there to now, where we have a 58% share of the market.

"Never did we think it would become as big as it has."

Today, EMIS employs almost 800 people and is based in Leeds and its new system EMIS Web is set to link GPs with other doctors.

Dr Sowerby is now worth an estimated £42m, and will share another £24m with the chairman of the company when EMIS raises £50m by floating 25% of its share capital on the Alternative Investment Market next month.

Dr Stables, now medical director of EMIS, will share £14m with two other directors.

Despite this, Dr Stables is still a regular visitor to the area as his mother lives in Sleights.

"My children grew up in the area so it is a very special place for me," he said.

"They went to Ruswarp Primary then onto Whitby School as it was.

"It was a great move for me obviously but I never thought when I moved to Egton all those years ago it would have come to this."

What do you think about this story? Have your say below.