Runners leave Conwy Castle at the start of the race

The event dubbed the world’s toughest mountain race got underway in north Wales today, with runners heading south from Conwy Castle in a five-day event.

More than 200 competitors started the Berghaus Dragon’s Back Race, with 315km (196 miles) of mountain running ahead of them.

Among the 223 were some of the world’s top ultrarunners, who will attempt the course down the spine of Wales, which includes 15,500m (50,850ft) of ascent, almost twice the height of Everest.

First runners are expected at the finish in Llandeilo in south-west Wales on Friday.

Over five days, competitors will have to navigate across wild, trackless, remote and mountainous terrain, finding checkpoints before cut-off times, and carrying essential kit at all times. Each night, they will stay at an official event campsite, before setting off on the next leg early the following morning.

Organisers said it is the toughest five-day mountain race in the world and fewer than half of those who start are expected to complete the course.

The 2017 Berghaus Dragon’s Back Race field is the biggest ever and includes some elite competitors. Notable runners include the 2015 winner, British runner Jim Mann, and Carol Morgan from Ireland, one of the favourites in the women’s race. In 2015, female competitors finished in second, fourth and sixth overall. Ultrarunning is a sport in which women race alongside the best male competitors on an almost equal footing.

Other notable participants in the 2017 Berghaus Dragon’s Back Race include Joe Faulkner, who is aiming to be the only person to complete every race since it was first held in 1992. Also setting out from Conwy this morning was radio and TV presenter Vassos Alexander, taking time out from the Chris Evans Breakfast Show on BBC Radio 2 to run through the Welsh mountains.

At the end of the first day, Jim Mann was leading the field, with Briton Sabrina Verjee the first woman to arrive at the Nantgwynant checkpoint.

The runners can be tracked via the Berghaus website.