IT has been billed as the king of all ultra-running races - and it proved too much even for the trio of hardened athletes vying for the crown.

The brutal inaugural run, called 'the Monarch's Way Ultra', began from the Old Powick Bridge on the outskirts of Worcester on Saturday.

But all three athletes who took part in the run, believed to be the longest and toughest in Britain, have now retired either through exhaustion or injury or a combination of both.

The word 'epic' is used far too liberally but it was certainly not misapplied in this case, a 615 mile slog which followed the escape route of Charles Stewart, later crowned Charles II, as he fled following his defeat at the Battle of Worcester, the last battle of the English Civil War, on September 3, 1651.

The men were hoping to complete around 43 miles per day and hoped to finish the challenge in around 10 days, a route

The route included such historic sites as Boscobel House and its Royal Oak, famous as a hiding place of the future Charles II, Stratford, the Mendip Hills and the Cotswolds before finishing at Shoreham-by-Sea on the south coast.

The three participants - Paul Ali, Allan Rumbles and Tim Welch, like Charles Stewart may have tasted defeat but it has not dulled their appetite for victory.

For organiser Lindley Chambers the run was always about living on the edge of what is possible and pushing the mind, body and spirit to its very limits and beyond.

He is determined the run will become a fixture in the ultra-running calendar and says this only throws down the gauntlet to others to see if they are tough enough to complete it.

Mr Lindley said: "It is one of the most extreme challenges out there. If they finish everything else, this is the one that might just finish them.

"I want it to be on the edge of what's possible. I'm not even sure it is possible. Only those who try to go too far can know how far they can go."

Paul Ali retired on the third day with a knee injury having completed 134 miles. Allan Rumbles retired on the third day with badly blistered feet and Tim Welch dropped on the fourth day suffering from exhaustion.

Mr Ali has twice completed the Spartathlon, a Herculean task which involves running from Athens to Sparta (250 km) within 36 hours.

Mr Rumbles has completed the Montane Spine Race, a 268 mile, non-stop, uncompromising winter challenge encompassing the entire Pennine Way and described as 'Britain's Most Brutal Race'.

The run, called 'the Monarch's Way Ultra' has been organised by Lindley Chambers of Braintree, Essex, an ex-soldier from the Royal Irish Regiment and a former firefighter.

The runners were Paul 'Smuggy' Ali, 44, of Reading, a business change manager at Covea Insurance who will be running in support of a children's hospice charity (Alexander Devine Children's Hospice Service), Allan 'I never get lost' Rumbles, 48, a builder from Wallington and Tim 'the cut off king' Welch, 45, of Lancashire, a director of finance with the Cheshire and Wirral Partnership who was fundraising for JDRF which aims to end type 1 diabetes which affects his second daughter.

The website is www.challenge-running.co.uk/monarchs-way-ultra.