to mind when most people think about Valentine's Day.

Few think of a beheaded priest, a martyred bishop or a pagan festival, but these are the roots of what has become one of the most romantic days of the year.

Many do not realise that with every romantic gesture, they are in fact celebrating a festival that predates Christianity.

For February 14 has been a celebration of romance since the days of the Roman empire.

Historians believe that Valentine's Day was originally a pagan festival, possibly Lupercalia, that was absorbed into the Christian calendar by early missionaries.

Lupercalia was dedicated to Pan, the god of fertility, and Juno, the guardian of women and goddess of married life.

One of the ceremonies of Lupercalia, where the names of young women were drawn from a box and allotted to available men, was practised in Europe right up until early this century.

Lupercalia was celebrated as winter drew to a close (mid-February) and the earliest spring flowers came into bloom, carrying with them thoughts of renewal and procreation.

The romantic element of St. Valentine's Day has become so strong that no one is clear which saint the Christians intended to commemorate on February 14.

There were at least two saints of that name and several martyrs because Valentine was a common name in ancient Rome.

Some say that St. Valentine was a Roman priest, who was beheaded on February 14, 269 after he had succeeded in converting his prison guard to Christianity while in jail for helping Christian martyrs.

Others say St. Valentine was a Bishop of Terni who was martyred in Rome. But what is widely agreed upon is that St. Valentine was regarded as the patron of lovers.

According to the Oxford Book of Encyclopaedic English, the tradition may be connected with the old belief that birds choose their mates on St. Valentine's Day -- a belief which has some foundation since certain species, including the partridge, select their mates in mid-February.

This view was confirmed by a spokesman for the Catholic Franciscan Order at St. Francis' Church in Glasgow's tough Gorbals district, once the city's worst slum.

For perhaps the oddest twist in the tale of the patron saint of romance is that Glasgow is the unlikely last resting place of his relics.