1 (1) John Caudwell £1.65 bn (£1.65 bn)

The name of former mobile phones magnate John Caudwell is well known worldwide. But this year it’s better known than it was in the Himalayas.

For John Caudwell was the major sponsor of the Caudwell Xtreme Everest expedition - a £1.5 million medical experiment to measure human systems in extreme environments.

The expedition, backed by a half-million pound Caudwell cash donation, was co-ordinated by the UCL Centre for Altitude, Space and Extreme Environment Medicine.

It involved doctors and scientists researching the effects of altitude and cold on human systems, increasing their understanding of critically ill patients.

In May, the expedition placed a research team on the summit of Mount Everest and made the first ever measurement of the level of oxygen in human blood at 8400m.

Expedition leader Dr Mike Grocott said John Caudwell’s enthusiasm for the project - along with his brother Brian - was invaluable.

"Once he heard in detail about the serious medical science being explored he decided to give the project his full support with a massive cash donation. John should be applauded for his far-sightedness and generosity," said Dr Grocott.

"Basically John has so much faith in this medical project he has decided to buy into it heart and soul, plus hard cash."

Caudwell will also be a more familiar sight in our homes later this year. He’s been signed up for the panel on the forthcoming series of the popular Dragon’s Den, replacing James Caan.

The Everest expedition is not all the hard cash John Caudwell has been ploughing into good causes. He has already raised more than £8 million for the Caudwell Children charity that helps children with medical conditions

Many thousands of sick and disabled children have benefited from his efforts.

He has devoted much of his time to charity work since the Caudwell Group, including the mobile phone empire which he founded - Phones4U - was sold to private equity firms Providence and Doughty Hanson & Co in August 2006.

The sale netted £1.46 billion.

When it was established, the firm took eight months to sell its first order of 26 phones. When it was sold, the Caudwell Group was selling 26 phones a minute and employed 8,000 people around the globe.

Fifty-five year old Shelton-born John Caudwell still lives close to his roots in Staffordshire, but now occupies a 50-room £7.5 million Jacobean mansion. He also has homes in Chelsea and Les Arcs in France.

His successful business career has also paid for a helicopter, a six-seater plane and a £1 million Sunseeker motorboat. And if you see a Bentley Azure with the number plate JC1, that’s John Caudwell driving it - not the Second Coming.

A self-confessed adrenaline junkie, his hobbies include riding fast motorbikes and he owns three of the fastest road-legal bikes in the UK.

But he knows how to take things easy as well, and can be seen chugging around his beloved Staffordshire - particularly the River Manifold and Churnet Valley - on his narrowboat.

Family and charities are keeping John Caudwell busy. But he’s a man with irons in the fire and many will be surprised if he’s away from the world of business for long.