St Valentine's Day is a holiday dedicated to lovers. It probably derives from the ancient Roman feast of Lupercalis (February 15th). Originally a festival for shepherds, it was celebrated in honour of Faunus (in Roman mythology, the grandson of the god Saturn). Its primary purpose was to secure fertility for the fields, the flocks, and the shepherds themselves. The festival gradually became associated with the feast day (February 14th) of two Roman martyrs, both named St Valentine, who lived in the 3rd century, but about whom nothing specific is known. St Valentine has traditionally been regarded as the patron saint of lovers. An early reference is found in the works of Chaucer (one of the greatest English poets, whose masterpiece, The Canterbury Tales, was one of the most important influences on the development of English literature), who states that birds pair on St Valentine’s Day. The practice of calling oneself a “Valentine” and asking one’s beloved to be the same, is referred to in the Paston Letters, the largest surviving collection of 15th-century English correspondence written by the Paston family and their neighbours in Norfolk.