Ultra Trail UK

Self-navigated running, UK

Centurion Running

Written by Catriona Adams. Published 12 August 2026

Centurion Running is the organiser behind twelve ultra-distance trail races across southern England, from 50km to 200 miles, run on historic long-distance paths — the South Downs Way, North Downs Way, Thames Path and Chiltern Way among them. Founded in 2010 by James Elson, it built its reputation on the fully supported, aid-station-staffed style of racing common in the US but rare in the UK at the time.

Key points

  • Founded in 2010 by James Elson; first event was the North Downs Way 100 in August 2011.
  • 12 events across southern England, from 50km to 200 miles, on historic trails like the South Downs Way and Thames Path.
  • The South Downs Way 100 (100 miles, 12,700 ft) is the toughest of the four 100-milers by climb.
  • The Centurion Grand Slam: finish all four 100-milers, or all four 50-milers, in one calendar year for a belt buckle.

The full portfolio

RaceDistanceClimb
Winter Downs 200200 mi22,500 ft
South Downs Way 100100 mi12,700 ft
North Downs Way 100103 mi11,000 ft
Winter Downs 100100 mi10,000 ft
Autumn 100100 mi5,000 ft
Thames Path 100100 mi1,900 ft
South Downs Way 5050 mi5,700 ft
North Downs Way 5050 mi5,600 ft
Chiltern Wonderland 5050 mi5,600 ft
Wendover Woods 5050 mi10,000 ft
Hundred Hills 50K31 mi4,000 ft
South Downs Way 50K31 mi3,800 ft

South Downs Way 100 and Autumn 100

The South Downs Way 100, run each June, is Centurion's flagship and the toughest of its four 100-milers by climb — around 12,700 ft over the chalk downland between Winchester and Eastbourne. The Autumn 100, run each October along flatter ground, carries roughly 5,000 ft of climbing and is a common choice for a first attempt at the distance precisely because the terrain, not the mileage, is what's forgiving.

The Grand Slam

Runners who finish all four Centurion 100-milers — South Downs Way 100, North Downs Way 100, Thames Path 100 and Autumn 100 — within the same calendar year earn a belt buckle under Centurion's Grand Slam, modelled on the American Grand Slam of Ultrarunning. A parallel Grand Slam exists across the four 50-mile races. Centurion is a partner of World Trail Majors, a separate ranking series from the UTMB World Series that Eryri by UTMB and Arc of Attrition belong to.

FAQ

Frequently asked questions

A UK ultra-trail race organiser founded in 2010 by James Elson, running 12 events across southern England on trails including the South Downs Way, North Downs Way and Thames Path.

Centurion's flagship 100-mile race, with around 12,700 ft of climbing — the most elevation of their four 100-milers, run each June along the South Downs Way.

A flatter 100-mile race with around 5,000 ft of climbing, run each October — a common choice for a first 100-mile attempt because of its comparatively gentle profile.

Completing all four Centurion 100-mile races — South Downs Way 100, North Downs Way 100, Thames Path 100 and Autumn 100 — within one calendar year, earning a belt buckle. A parallel Grand Slam exists for the four 50-mile races.

In 2010 by James Elson, with the first event — the North Downs Way 100 — held in August 2011.

No — Centurion is a partner of World Trail Majors, a separate ranking series, not the UTMB World Series that Eryri by UTMB and Arc of Attrition belong to.

Sources for this page

Related