The modern-day Halloween is largely agreed to have originated from the ancient Celtic festival of Samhain, held around 1 November, the date that marked the transition from autumn to winter. It was this time of year where people believed the boundary between the worlds of living and dead became blurred, and was when the souls of the dead were said to revisit their homes.
In the era of Christianity, this tradition became absorbed into the celebration of All Saints Day, held on 1 November, dedicated to honouring all saints and martyrs. The 2 November became All Souls’ Day, a day to honour the dead, and here many of the Celtic traditions, such as bonfires, parades and dressing up in costume, blurred with Christian celebrations, to form festivities accepted, and even encouraged, by church authorities.
All Saints Day later became known as All-Hallows and from this the night before came to be referred to as All-Hallows Eve. From this term derived the name ‘Halloween’, the name for the beginnings of the festival that was celebrated across Europe in the early Middle Ages, and stuck even as the religious celebrations fell out of favour in later centuries.