Imagine a game of football played not with 11 but hundreds of players on each side; contested not on a soft field of grass but on cold, hard flagstone streets; and where there are no rules and no referee to control the surging mass of bodies.

Though it might sound like something from the Middle Ages, in fact just such a game of mob football is played every year in Scotland.

Known as The Ba’, the game is played each Christmas Day and New Year’s Day through the narrow, winding streets of the town of Kirkwall in the Orkney Islands off the north coast of Scotland.

Steam rising above the ruck of players

To onlookers it can be impossible to tell where the ball is amongst thehuge scrum of players who risk ofcracking ribs and breaking limbsto try and score a match-winning goal.

The men and boys of Kirkwall are divided into two teams of ‘Uppies’ and ‘Doonies’ depending on which part of the town they come from.

There are no goalposts or goalkeepers, and the two sides compete to score a goal by transporting the Ba’, which is a cork-filled, leather ball, to the other end of town.

Games can last for hours as the heaving ruck of players struggle to gain ground in either direction, though the ball can suddenly burst out of thepack and into a small side street.

The game has its roots in more violent forms of street football which have taken place in towns across Britain since Roman times, though these days injuries are surprisingly uncommon.

Nonetheless, shopkeepers whose premises line the streets take no chances and board up their doors and windows to prevent them being smashed by the sheer weight of bodies who funnel through the narrow streets.

Finally, when a goal is scored, the Ba’ itself is awarded to a key member of the side who can proudly display the trophy in their window, but not before a celebratory festive drink with the team.