Saint Valentine's Day or Valentine's Day falls on February 14. It is the traditional day on which lovers express their love for each other; sending Valentine's cards and candy, often anonymously. The holiday is named after two men, both Christian martyrs named Valentine. The day became associated with romantic love in the High Middle Ages, when the tradition of courtly love flourished.

February 14 was traditionally dedicated to two ancient martyrs named Valentine. They are listed in early martyrologies under the date of February 14, which is likely the date of their deaths. There is a third St. Valentine from Africa who was also martyred on February 14, but he did not get a saint's day. Very little historically accurate information exists on any of these Valentines. The Valentines honored on February 14 are:

• Valentine of Rome (Valentinus presb. m. Romae): a priest in Rome who suffered martyrdom about AD 269 and was buried on the Via Flaminia. His relics are at the Church of Saint Praxed in Rome and at Whitefriar Street Carmelite Church in Dublin, Ireland. According to a biography of Saint Valentine by Robert Sabuda, the priest was also a doctor who would treat patients even if they could not pay him. It is said his miracle was curing a difficult case of blindness in a young girl.
  

• Valentine of Terni (Valentinus ep. Interamnensis m. Romae): He became bishop of Interamna (modern Terni) about AD 197 and is said to have been killed during the persecution of Emperor Aurelian. He is also buried on the Via Flaminia, but in a different location than Valentine of Rome. His relics are at the Basilica of Saint Valentine in Terni (Basilica di San Valentino).

In 469 A.D. Pope Gelasius set February 14th as a day to honor him. Saint Valentine became the patron saint of epilepsy; having suffered from it in life. Saint Valentine also became the patron saint of lovers as the church assimilated the fertility festival Lupercalia into their calendar.

The association of the middle of February with love dates to ancient times. On the ancient Athens calendar, the period between mid-January and mid-February was the month of Gamelion, dedicated to the sacred marriage of Zeus and Hera.

Lupercalia or Februarca, The Feast of Purifcation, used to be on February 15th and contained priests called Luperci who prayed to the wolf deity Lycaeus at the cave of Palentine. Lycaeus was the mother of the founders of Rome, Romulus and Remus. Marc Antony was master of the Luperci priests during his lifetime and in 44. B.C. offered the crown to Julius Caesar. The names Lyceum Temple of Love and February pure remain in the language today.

Valentine's Day in North America

Valentine's Day was probably imported into North America in the 19th century by British settlers. In the United States, the first mass-produced valentines of embossed paper lace were produced and sold shortly after 1847 by Esther Howland (1828-1904) of Worcester, Massachusetts. Her father operated a large book and stationery store, and she took her inspiration from an English valentine she had received. Since 2001, the Greeting Card Association has been giving an annual "Esther Howland Award for a Greeting Card Visionary".

In the second half of the 20th century, the practice of exchanging cards was extended to all manners of gifts in the United States, usually from a man to a woman. Such gifts typically include roses and chocolates. In the 1980s, the diamond industry began to promote Valentine's Day as an occasion for giving jewelry.

The day has come to be associated with a generic platonic greeting of "Happy Valentine's Day."

Those without a significant other sometimes speak with sarcasm by referring to Valentine's Day as "Singles' Awareness Day".

In some North American elementary schools, students are asked to give a Valentine card or small gift to everyone in the class. The greeting cards of these students often mention what they appreciate about each other. Though this practice has been criticized for possibly being irrelevant or inappropriate, it has continued for decades.

Source: Wikipedia