January is a month of doors and thresholds: the month of Janus, god of beginnings and endings, transitions and entrance ways, who looks both backwards and forwards. In medieval calendars, January is typically represented by an image of the double-faced Janus sitting at a feast, warming himself against the winter chill. Having two faces means he gets to enjoy twice the feasting – he is often shown holding a plate of food up to one mouth, a cup of drink to the other. It is a cheerful image with which to begin a new year.

Of course, there’s a serious point behind that playful iconography. Like Janus, we all find ourselves in January looking back over the past year and ahead into the year to come. We take stock, but also try to peer into the future. Most traditional New Year superstitions rely on the idea that the first thing you do after the start of the year is predictive, foretelling how the rest of the year will go – hence ‘first-footing’, where the first visitor to come over the threshold is supposed to bring in luck. Today, those who would not consider themselves remotely superstitious still participate in their own January rituals of forecasting, as newspapers ask experts to provide their predictions for the year ahead. Even historians, who by choice tend to direct our gaze backwards into the past, are probably tempted at this time of year to share the half-hopeful, half-fearful glance into the unknown future.

Jolly as Janus might be, though, it is not always wise to try to look too far ahead. As an anonymous 14th-century poet wrote, with a wry allusion to New Year festivities, in Sir Gawain and the Green Knight (probably the greatest poem in the English language about the meeting of the old year and the new):

For thagh men ben mery quen thay han mayn drynk, 
A yere yernes ful yerne, and yeldes never lyke;
The forme to the fynisment foldes ful selden.

(For though men may be merry when they’ve had mighty drink,
A year runs very swiftly, and yields never the like again;
The first and the finishing fit seldom together.)

Many people who tried to foretell the course of the year in January 2020, with the pandemic approaching but still hazy on the horizon, were rapidly proved wrong; last year, amid the winter lockdown, all kinds of prediction seemed hazardous. This year might be different – but who really knows what it will yield?

Back to doors and thresholds. For a current project, I have been thinking about one particular year when the cusp of December and January proved momentous. It was midwinter, 1065. Edward the Confessor, the ageing and childless king of England, was overseeing the culmination of a long-term project close to his heart: the consecration of the royal church he had rebuilt at Westminster Abbey.

The consecration took place within the Twelve Days of Christmas, on 28 December, Childermas Day. By Twelfth Night, Edward was dead, buried within his new church, as the Bayeux Tapestry depicts. Swiftly crowned in his place was Harold Godwineson – and the story of what unfolded over the year that followed is one of the best known in British history. It was a year that changed England forever and no one saw it coming; ‘the forme to the fynisment’ could hardly have been less in accord. Yet the year ended with an echo of its beginning: at Christmas 1066, Westminster Abbey saw another coronation, this time of William the Conqueror.

Incredibly, there is a door still to be found at Westminster Abbey which stood witness to all these events. It is the oldest door in Britain and the only one surviving from the Anglo-Saxon period. Dendrochronology has dated it to the mid-11th century: the oak tree from which it was made grew in eastern England between the 920s and 1030s and the door was constructed in the 1050s, as Edward’s church was being built. While the rest of the church has been remodelled over the centuries, this door has been retained.

Plain enough to look at, this simple and sturdy door is a remarkable survival. It was there when the church was consecrated, when Edward was buried and when William was crowned. It has seen many years end and many begin. On the threshold of this new year, it feels like a more trusty symbol than two-faced Janus at his feast: a reminder that what you need is not the power to know what might happen in the future, but only the strength to endure.

Eleanor Parker is Lecturer in Medieval English Literature at Brasenose College, Oxford and writes a blog at aclerkofoxford.blogspot.co.uk.