'It's important to bear in mind that I don't think people have changed,' said Professor Ashe. 'People in every time and culture have fallen in love, but not every culture has written about love or valued it in the same way.

'In the 12th century, romantic love became something that was worth celebrating and exploring in songs and stories - and you only have to look at modern film and music to see that legacy is still with us.'

Before the Norman conquest of England, Anglo-Saxon literature had a very different focus, said Professor Ashe.

'The world of the Anglo-Saxon warrior, at least in poetry, was based on the bond of loyalty between fighting men. Love in this world means love for your fellow warriors and the idea of sacrificing yourself for the group.

'In this setting, it's absurd that you might pursue personal happiness because that could mean running away and abandoning your companions.'

In Classical literature, too, heroism leaves no time for a personal life. 'Of course, the heroes of the Greek and Roman epics manage to do great deeds, but they still have to die heroically or sacrifice themselves in other ways to a heroic destiny,' said Professor Ashe.

So what changed in the Middle Ages?

'There was a transformation in culture,’ said Professor Ashe. ‘A series of church reforms in the 12th century took Christianity from a rather austere view of God the Father to a new focus on Christ's humanity.

'The spiritual lives of ordinary people were recognised, and people were encouraged to have a more emotional and personal relationship with God as individuals. And romantic love - giving yourself to another person - provides a justification, in the medieval moral compass, for the pursuit of self-fulfilment as an individual.

'Even tragic love stories are based on the idea that the living individual is to be celebrated and that it might be better to stay alive after all.'

Professor Ashe explained that changing attitudes towards the roles of men and women may have played their part. 'These church reforms codified that marriage is a sacrament requiring free consent from both parties: the woman's choice was actively required,' she said.

'In addition, the rise of the aristocracy and a culture of conspicuous consumption created a courtly audience for romance literature, with many wealthy female patrons. Where once literature had been produced – and largely read – by monks, now the patrons and audience of literature were increasingly lay people, and women as well as men.'

In the years after the Norman conquest, most English writers worked in French or Latin. Professor Ashe's forthcoming book, Early Fiction in England (Penguin, 2015), will provide translated selections from the most important of these works.

'A lot of the 11th-12th century work has been neglected because it's not in English,' said Professor Ashe. 'Or else people make too much of the choice of language. I don't believe it's a political choice so much as a pragmatic one.

'It's only recently that we've begun to recognise these works as 'English' literature, and to acknowledge the impact that they had on the better-known later English writers, such as Geoffrey Chaucer.'

Why are we still so interested in reading about love?

'The tragic love story sometimes seems like a contradiction in terms,' said Professor Ashe, 'Why is it enjoyable to read sad stories? There are many possible explanations, but I think one factor is that in a tragic story, sorrow is made into a meaningful pattern, even into something beautiful.

'If you allow that pain can be profound in literature, it creates a space for your own emotions to seem meaningful rather than chaotic. In the Middle Ages, the idea that suffering was in some way productive was very widespread.

'Our understanding of suffering has changed, but tragic stories still exist. Perhaps it's because there is some pain which we can't alleviate, and these stories make that more bearable.'

Read the full article on the Oxford University Arts blog.