This weekend, adults and children alike are donning vampire fangs and cheap wizard costumes, during one of the biggest shopping times of the year. Halloween used to be more about bobbing apples and recycling old sheets for costumes, but since the 1990s the commercialisation of the holiday has accelerated, with large stores stocking Halloween costumes and other merchandise from early September.

The origins of the festival lie in celebrating the pagan new year, which runs into All Saints’ Day, on November 1st. In pagan times, a fire was built on October 31st in honour of the sun god. The trick-or-treat element of Halloween possibly began in the UK with poor people knocking on doors and receiving food in return for the promise of prayers.

Ireland is thought to have given Halloween the pumpkin tradition, in a nod to an Irish folk tale. There is a long tradition here of carving lanterns out of vegetables, including turnips and cabbages. The size and colour of the pumpkin made it appear spookier than most other vegetables. Last year Tesco reported a 30 per cent increase in demand for pumpkins, with more than 50,000 sold during Halloween.