Someone who became Bishop of Poitiers in about 350AD may not seem a likely candidate for much mention in modern-day Oxford, but his name will, probably unwittingly, be much on the lips of undergraduates and dons during the coming week; for he was St Hilary, after whom the university’s winter term is named.

He was of huge importance in the early western Christian Church, since he saw off, with his fierce writings, the so-called Arian heresy which threatened the very existence of Roman Catholicism by undermining belief in the Trinity (the name, of course, of another University term).

The first Sunday after his feast day (January 13, traditionally the coldest day of the year) marks back-to-work time for Oxford scholars who in the Middle Ages would have had little time for study over the 12 days of Christmas. Indeed, celebrations of Epiphany (January 6) sometimes continued for a week even after Christmas itself had ended, taking them right up to St Hilary’s Day without much of a break in their eating and drinking and general merry making.

The annual one-day exhibition at the Bodleian this Christmas focused on Epiphany and I, for one, found that a quick visit to the Divinity School to look at illuminated manuscripts – including a 12th-century English depiction of the Magi bearing gifts – a welcome break in a day of Christmas shopping for modern-day presents.

Epiphany, Greek for manifestation, celebrates the manifestation of Christ to the the Three Magi or wise men. Until the 19th century it was second only to Christmas Day for eating and drinking – indeed, many of us would very probably have hangovers this morning were it not for the decline of Twelfth Night celebrations during Victorian times. Wage-slaves among us might also be interested to note that the Council of Tours in 567 AD stipulated that Christmas should last 12 days and that no one should have to work during that period.

The Magi were later identified with kings, of three races and of three ages (youth, middle, and old-age), and even today an offering of gold, frankincense and myrrh is made on the Queen’s behalf during Holy Communion in the Chapel Royal at St James’s Palace, London, on January 6 each year. Until the reign of George II, the ceremony was carried out by the king in person.

When Britain finally bowed to the inevitable and accepted the Gregorian Calendar in 1752, 11 days were suddenly ‘lost’. This caused particular confusion around Christmas and New Year as the 11 days almost coincided with the 12 days of Christmas, with old-style Christmas Eve getting muddled up with new-style Twelfth Night.

Particularly in West Oxfordshire and Gloucestershire, many people decided to celebrate Christmas on January 6. They said Christmas obviously fell on that date since it was then that the cattle went down on their knees! They stoutly maintained that though they had not seen this happen themselves, their parents or grandparents had.

In the Oxfordshire Cotswold countryside, January 7 also had particular significance for women as this was the day that they would resume their work of spinning the woollen yarn. The day was known as St Distaff’s Day – even though no such saint ever existed. A distaff was an implement used for spinning before the invention of the spinning wheel and it became so closely associated with the work of spinsters that the ‘distaff side’ became the phrase used for describing the female side of a family.

A poem called St Distaff’s Day or The Morrow after Twelfth Day, written by Robert Herrick in 1648, describes how young men would on this day try to steal some of the the girls’ yarn and burn it; and how the girls would retaliate by soaking them with water.