Christmas is steeped in nostalgia - that's the point of it. We reminisce about our own past, observe (or rebel against) our family traditions, and fondly assemble a pastiche of European history - a bit of Victoriana and a lot of the middle ages. The Christmas cards arriving on the doormat with their exquisite medieval illuminations, the visits to the medieval churches and cathedrals: Christmas wouldn't be Christmas without fond nods to our medieval past.
It reflects a curiously persistent appetite. It seems as if few children's blockbuster films can get away without referencing the middle ages. Even if the latter don't dominate the script, they are cluttering up the background. While Narnia, Lord of the Rings and Shrek, in their very diverse ways, all handsomely stock their plots with medieval props such as castles, queens and knights, even Harry Potter and the recently opened Golden Compass use medieval associations to inject that sense of epic struggle from an era in which heroism and its triumph were still credible.
The "medieval" has become a form of cultural shorthand, and it serves many purposes. It's not just about plotlines or a stunning aesthetic - it is also used as a pejorative term. People talk of Africa as medieval, or argue that Islam is "stuck in the middle ages". Medieval becomes synonymous with hard, short lives, barbarism, and a brutal, arbitrary use of violence. We are both captivated and repelled by this period of our past.
Dig a bit deeper and some fascinating explanations emerge of why the medieval should still have such cultural currency. For all the huge differences between today and 12th-century Europe, there are also remarkable parallels which, arguably, bring these two societies closer together than any in the intervening period. First, we share pervasive anxiety about an apocalypse: while we fear climate change our medieval counterparts feared the end of the world. Second, we share a fear of Islam and uncertainty about how to deal with it. Should we fight it (as they subsequently did in the Crusades) or attempt to win converts? Islam's capacity to exert such a powerful hold over its growing number of followers left 12th-century Europe baffled and insecure about its own certainties. Does that sound familiar?
Third, the emergence of a cash economy for the first time since antiquity prompted deep concern. The pursuit of profit produced inequality and contemporaries bewailed the breakdown of community and family. Finally, there was a crisis of authority in 12th-century Europe, with the church and nobility riddled with corruption and a revolution in government as it sought to expand its power into its subjects' lives. Our corollary is a political process eviscerated by apathy and disillusionment, while the state insists on acquiring unprecedented new powers through ID cards, DNA databases and surveillance.
So far, drawing up such similarities sounds like a historians' parlour game, a sort of mix and match, but so what? But this is where it becomes deadly serious. How did our 12th-century forebears deal with all this insecurity and dramatic change? They invented a persecution society, one that systematically identified whole categories of people and then set about exterminating, subjugating or segregating them. Just as the origins of modern Europe and its global expansion can be tracked back to the momentous political and economic changes of the 12th century, so can its corollary, a state built to persecute minorities, which has intermittently characterised Europe's history ever since.
This is the argument brilliantly explored in one of the most influential and controversial books of medieval history of the last 20 years, RI Moore's The Formation of a Persecuting Society. The relevance of its argument today is uncanny. Moore demonstrates that the demonisation of the Jews and the emergence of systematic antisemitism was part of a broader process in which the threat from very disparate groups of people was inflated - heretics, gays, lepers all become subjects of new legislation - and new methods of intervention in the lives of individuals, including inquisition and torture, were invented.
Some of the results of the "persecuting society" are well known. The position of Jews deteriorated all over Europe, their lives circumscribed by punitive regulations and mass murders. There was the brutal persecution of Cathar heretics in south-west France and its invention of the inquisition. Lepers were deprived of civil rights, rounded up and confined.
European attitudes towards Islam fit into the thesis. They deteriorated sharply in the 12th century and an initial curiosity gave way to abusive prejudice. There was a process of deliberate forgetting of the great achievements of Islamic scholarship which had been known a century earlier - Europe simply lost interest in learning Arabic, indeed learning anything more from its much more scholarly Muslim neighbours.
This prejudice, this impulse to stigmatise and persecute, was not a reaction to a new threat. There had always been plenty of Jews, heretics and homosexuals and, of course, they had been the subject of violence before, but not in the 12th-century version of a deliberate and socially sanctioned violence by the state and other institutions.
The persecution was not a response to Jews becoming rich from usury (as the history used to run) but a response of a society in tumultuous change as powerful interests sought to take advantage. Crucially, the state and its new functionaries were intent on expanding their power, and used persecution of entirely new "crimes" as a way to develop the machinery and legitimacy with which to exercise this new power.
It's a legacy that Moore argues has plagued European history, erupting each time with greater force and more devastating consequences. One can see the pattern in 16th-century witchcraft trials and religious persecution, right up to the Holocaust or the informants of the German Democratic Republic. All follow a pattern first laid down between the 11th and 13th centuries, even if many of the circumstantial detail differs.
Frequently, as you read Moore, the modern-day parallels make the hairs on the back of your neck stick up. We are now witnessing a concentration of power in a political/economic elite that is struggling to assert its legitimacy at the same time as extending its power (through such measures as the proposed extension from 28 days' detention, for example). Crucially useful to it in doing that is the increasingly harsh rhetoric now endemic in public debate, as new groups are identified as threats - Muslims, asylum seekers and irregular migrants - and the scale of those threats is absurdly inflated.
It makes a mockery of the idea that we use "medieval" as a term of abuse to fling at others, when really it's a term that correctly defines enduring and deeply shameful characteristics of our own society against which history warns us to be scrupulously vigilant. Moore admits that there have been periods of recession in our persecuting tendencies over the past 600 years. But the horrific lessons of the 20th century can leave us no room for the complacent belief that this weapon of political advancement has become redundant.