‘We have often heard that people call [1 January] ‘Year’s Day’, as the first day in the year’s cycle, but we do not find any explanation in Christian books why this day should be appointed the beginning of the year… Our calendar begins on this day according to the Roman practice, not for any holy reason, but because of ancient custom.’

This is the Anglo-Saxon writer Ælfric of Eynsham, at the end of the tenth century, puzzling over an oddity of the calendar which persists to this day. As he says, the practice of beginning the year at the start of January originated with the Roman calendar. When the Anglo-Saxons converted to Christianity in the seventh century, they adopted that calendar along with the new religion, including the January date for the new year. This date must have seemed fairly random to them, since in Britain there wasn’t any wider cultural or seasonal significance to support it: it wasn’t the date of the winter solstice, or a religious festival, just an accident of calendar history.

January 1 might have been called ‘Year’s Day’ in England by the tenth century, but it was very much overshadowed by Christmas. Many of Ælfric’s Anglo-Saxon contemporaries seem to have felt Christmas, not January, was the real beginning of the year – and unlike the Roman date, that was a belief with deep cultural roots. Before the conversion the Anglo-Saxons had begun their year at the winter solstice, the turning point of the solar year. That’s when the days begin to grow longer after the shortest day, when the darkness gradually recedes and it starts to feel possible to think about new life and returning spring.

After the conversion, it was natural for Christmas to inherit this role in the calendar. Not only was Christmas closely linked to the solstice in medieval thinking, but the birth of Christ marked the ultimate new beginning: the eternal God’s entry into time and the start of the Christian story, initiating not just a new year but a new era in history. No wonder it seemed more meaningful than a date borrowed from the Roman calendar. So where did New Year’s Day fit in?

Even today, Christmas and New Year have a rather ill-defined relationship in British culture. For some people both events are part of one long festive season, but there are also people who strictly separate the two, packing the Christmas decorations away before breaking out the New Year’s Eve champagne. Some are on holiday right through the period, others go back to work between Christmas and New Year.

As if reflecting this uncertainty about the connection between the two holidays, in recent years there’s been a trend for coining jokey names to describe the in-between period after Christmas and before New Year: ‘Twixmas’ and ‘Chrimbo Limbo’ are two (cringeworthy) examples. It’s a time for which we don’t now have an established name, or much shared cultural understanding.

Names like ‘Twixmas’ are an attempt, consciously or not, to make up for the loss of the venerable old name which did once describe this season: the Twelve Days of Christmas. We still have this phrase, though many people now only know it as the theme of a Christmas carol. There’s an increasingly common misconception that it refers to the twelve days before Christmas rather than the days after – blame the advertisers for that, who’ve seized on it as a countdown to encourage last-minute Christmas shopping.

In the Middle Ages, however, the Twelve Days of Christmas formed a clearly defined season with its own character and rhythm, spanning the old year and the new. Over the course of the medieval period, the calendrical oddness which frustrated Ælfric was resolved by the integration of 1 January into this season, giving the apparently random date of the Roman New Year a more coherent place in the British calendar.

The Twelve Days of Christmas go back a very long way – in England at least as far as the ninth century, when they were designated as a holiday in Anglo-Saxon law. As well as giving people the opportunity to celebrate Christmas, this recognised that little work could be done then in any case; the dead of winter, when daylight is scarce and the weather bitterly cold, is a bad time for working outdoors. These in-between days at the turning of the year are for indoor pleasures, finding company and warmth wherever you can.

The medieval Twelve Days weren’t only about Christmas itself, though that was the major theme of the festivities. The most important of the days were the first and last of the sequence, Christmas and Twelfth Night (5 January), the eve of the Epiphany, which marked the culmination of the season. Between them there was a chain of smaller celebrations, each with its own stories and customs attached.

First came the feasts of St Stephen and John the Evangelist on 26 and 27 December, followed by ‘Childermas’ on 28 December, the feast of the Holy Innocents, commemorating the children slaughtered by Herod as he tried to kill the infant Christ. In the later Middle Ages these days were joined by the feast of the martyr Thomas Becket, one of England’s most popular saints, whose murder on 29 December 1170 gave him a place within the Twelve Days too.

The mood of this season was variegated – light and shade, not constant full-out festivity. Childermas in particular was a sombre day, popularly believed to be the unluckiest day of the year. The legends and art connected with St Stephen, stoned to death as the first Christian martyr, and Thomas Becket, brutally killed in his own cathedral, are blood-stained and violent, far from anything we would consider Christmassy.

Coming just over halfway through the Twelve Days, the New Year brought another shift in mood. Importantly for its medieval associations, this too was a Christian feast-day: 1 January is the eighth day after Christmas, which meant it was the day when Jesus was circumcised according to Jewish law. The first feast of the medieval calendar year was the Circumcision of Christ, and it was seen as an important part of the Christmas story – a marker of Christ’s Jewish identity and his fleshly, vulnerable humanity. This was the first time Christ’s blood was shed, medieval sermons say, so it foreshadowed his future death, looking ahead from Christmastide to Easter. Preachers also drew a connection with Jesus’s naming and therefore with baptism, rebirth and new beginnings – appropriate New Year themes.

There were secular customs associated with the New Year, too. In late medieval Britain, New Year’s Day – not Christmas – was the one day in the season for exchanging presents. These weren’t Christmas presents; they had a specific purpose, because the idea was that giving someone a gift on New Year’s Day would bring them good luck and prosperity in the coming year. It was an ‘old custom’, says one medieval writer, that on New Year’s Day ‘they that be knit together by love specially [are accustomed] to give each other year’s-gifts and desire good year to come to them.’

Among the aristocracy, these ‘year’s-gifts’ could be lavish, but if you couldn’t afford a gift some other token would do. There was a fashion for composing poems as New Year presents for lovers or patrons. The Scottish poet William Dunbar wrote one for James IV, wishing the king ‘Joy, gladness, comfort and solace’ as his New Year gift, while a poem by the fifteenth-century writer John Lydgate has a lover exclaiming ‘alone upon the New Year night, I prayed unto the frosty moon’ to send love to his lady. An anonymous poem from around the same time begins:

Jewels precious can I none find to sell

To send you, my sovereign, this New Year’s morrow,

Wherefore, for luck and good hansell,

My heart I send you.

A ‘hansell’ was a gift given at the beginning of any new undertaking, meant to bring good fortune with it. After Twelfth Night, the time would come to get back to work: the turn of the year was over, and even in the mirk of January the light was gaining ground. If you had received a hansell, you could carry good luck with you into the year ahead.