It may not quite match Eddie Izzard’s feat of completing 43 marathons in 51 days.

But, when Monmouth man Kristian Williams, 24, competes in the London Marathon, he will be attempting to finish 21 charity runs in 10 months- one for every year lived by his friend, who was killed in Afghanistan.

The effort is in memory of Jamie Gunn, a friend at Monmouth Comprehensive and someone he describes as “the funniest person I knew”.

Rifleman Gunn of First Battalion, The Rifles, was killed in Helmand Province last February when a Land Rover he was travelling in came in contact with a landmine.

Rifleman Gunn and Mr Williams- a former Lance Corporal in the Royal Logistics Corps- were planning to run Monmouth’s Kymin Dash last July to see “who was the fittest”.

Mr Williams, a sales consultant, said: “When I heard he had been killed, I didn’t want to forget the plans because he couldn’t be there with me, but wanted to make it one of many runs to celebrate Jamie’s life.”

Mr Williams has since completing the Silverstone, Marlow and Wycombe half marathons, the Exeter Commando Challenge and Grim Eight organised by the Army in Aldershot.

He is running the London Marathon with another friend of Rifleman Gunn's, Emma King, 29, from Monmouth.

The pair are raising funds for the Army Benevolent Fund, which helped Mr Gunn’s family. The aim is to raise around £3,000, with Miss King’s employer, Barclays Bank, pledging to match whatever is raised.

There will also be a fundraiser in Rifleman Gunn's memory at Bridges Community Centre, Monmouth, on Saturday, April 10. This features a band, disco and hog roast from 7.30pm.

For details, call 07841135737. To donate, visit www.justgiving.com/jamiegunn.