He kicked off five days of festivities celebrating the lives of the Norse invaders and their enduring legacy to York.

His official opening of the festival in Coppergate was followed by a combat display by members of the four Viking nations of Norway, Sweden, Denmark and the Danelaw.

Mr Snow then he led the combatants through the half-term crowds in the busy city centre to St Sampson's Square, for presentations to young artists who had entered a competition to design their own warrior.

He also gave a lecture at the Tempest Anderson Hall, about English battlefields, with a particular focus on the significant clashes of the 11th century, but the festival, which continues until Sunday, also explores the peaceable activities of the Vikings, their day to day lives and their culture.

There will be more fighting on Saturday, as weapon drills and last-minute preparations add to the building tension throughout the morning, culminating in a fight for supremacy over the city in the Eye of York at 2pm.

More details of the festival programme can be found at www.jorvik-viking-centre.co.uk/