South Africa, Feb. 14 -- In the UK, it is estimated that 60% of the population will celebrate Valentine's Day this year, each spending around £52 on gifts and other romantic gestures. The total spend in the US will be about $27bn (£22bn), including roughly $500m on roses.

So the tradition of spending money on your romantic partner on 14 February seems fairly well established. But it is hard to know exactly when the link began.

Up until the late 14th century, Valentine's Day was solely a commemoration of his martyrdom. The shift toward an association with romantic love emerged in the Middle Ages, and is often attributed to the poet Geoffrey Chaucer, who linked Valentine's Day to romance in his poem Parliament of Fowls.

But it ...