Samhain was one of four significant seasonal festivals in the Celtic calendar. These all centred around important times in nature and farming, heralding the beginning of new seasons and new activities. They were called Imbolc (February), Beltane or Beltene (May), Lughnasadh (August) and Samhain (October).
Samhain marked the end of the harvest and the beginning of winter, the darker half of the year. It was traditionally celebrated on the evening of the 31st October and the 1st November and has now become the modern day Hallowe'en.
Samhain is the time of year when livestock would be brought in from the fields and it was also believed that the Otherworld could briefly become visible in the land of humans. This connection with the supernatural is a key feature of the modern day Hallowe'en celebrations. As with many other Celtic festivals, fires would have been lit and feasts were prepared as part of the celebrations.