Readers have uncritically assumed that Chaucer was referring to February 14 as Valentine's Day. Henry Ansgar Kelly has observed that Chaucer might have had in mind the feast day of St. Valentine of Genoa, an early bishop of Genoa who died around AD 307; it was probably celebrated on 3 May. A treaty providing for Richard II and Anne's marriage, the subject of the poem, was signed on May 2, 1381.
The earliest description of February 14 as an annual celebration of love appears in the Charter of the Court of Love. The charter, allegedly issued by Charles VI of France at Mantes-la-Jolie in 1400, describes lavish festivities to be attended by several members of the royal court, including a feast, amorous song and poetry competitions, jousting and dancing. Amid these festivities, the attending ladies would hear and rule on disputes from lovers. No other record of the court exists, and none of those named in the charter were present at Mantes except Charles's queen, Isabeau of Bavaria, who may well have imagined it all while waiting out a plague.
The earliest surviving valentines in English appear to be those in the Paston Letters, written in 1477 by Margery Brewes to her future husband John Paston "my right well-beloved Valentine".
Jack B. Oruch notes that the date on which spring begins has changed since Chaucer's time because of the precession of the equinoxes and the introduction of the more accurate Gregorian calendar only in 1582. On the Julian calendar in use in Chaucer's time, February 14 would have fallen on the date now called February 23, a time when some birds have started mating and nesting in England.
In 1797, a British publisher issued The Young Man's Valentine Writer, which contained scores of suggested sentimental verses for the young lover unable to compose his own. Printers had already begun producing a limited number of cards with verses and sketches, called "mechanical valentines." Paper Valentines became so popular in England in the early 19th century that they were assembled in factories. Fancy Valentines were made with real lace and ribbons, with paper lace introduced in the mid-19th century. In 1835, 60,000 Valentine cards were sent by post in the United Kingdom, despite postage being expensive.
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, but Howland took her inspiration from an English Valentine she had received from a business associate of her father. Intrigued with the idea of making similar Valentines, Howland began her business by importing paper lace and floral decorations from England. A writer in Graham's American Monthly observed in 1849, "Saint Valentine's Day ... is becoming, nay it has become, a national holyday." The English practice of sending Valentine's cards was established enough to feature as a plot device in Elizabeth Gaskell's Mr. Harrison's Confessions (1851): "I burst in with my explanations: 'The valentine I know nothing about.' 'It is in your handwriting', said he coldly." Since 2001, the Greeting Card Association has been giving an annual "Esther Howland Award for a Greeting Card Visionary".
In 1868, the British chocolate company Cadbury created Fancy Boxes – a decorated box of chocolates – in the shape of a heart for Valentine's Day. Boxes of filled chocolates quickly became associated with the holiday. In the second half of the 20th century, the practice of exchanging cards was extended to all manner of gifts, such as giving jewelry.
In Japan, Morozoff Ltd. introduced the holiday for the first time in 1936, when it ran an advertisement aimed at foreigners. Later, in 1953, it began promoting the giving of heart-shaped chocolates; other Japanese confectionery companies followed suit thereafter. In 1958, the Isetan department store ran a "Valentine sale". Further campaigns during the 1960s popularized the custom.
In Saudi Arabia, in 2002 and 2008, religious police banned the sale of all Valentine's Day items, telling shop workers to remove any red items, because the day is considered a Christian holiday. This ban has created a black market for roses and wrapping paper. In 2012, the religious police arrested more than 140 Muslims for celebrating the holiday, and confiscated all red roses from flower shops. Muslims are not allowed to celebrate the holiday, and non-Muslims can celebrate only behind closed doors.
Islamic officials in West Malaysia warned Muslims against celebrating Valentine's Day, linking it with vice activities. Deputy Prime Minister Muhyiddin Yassin said the celebration of romantic love was "not suitable" for Muslims. Wan Mohamad Sheikh Abdul Aziz, head of the Malaysian Islamic Development Department (Jakim), which oversees the country's Islamic policies said that a fatwa (ruling) issued by the country's top clerics in 2005 noted that the day 'is associated with elements of Christianity,' and 'we just cannot get involved with other religions' worshipping rituals.' Jakim officials planned to carry out a nationwide campaign called "Awas Jerat Valentine's Day" ("Mind the Valentine's Day Trap"), aimed at preventing Muslims from celebrating the day on February 14, 2011. Activities include conducting raids in hotels to stop young couples from having unlawful sex and distributing leaflets to Muslim university students warning them against the day.
The U.S. Greeting Card Association estimates that approximately 190 million valentines are sent each year in the US. Half of those valentines are given to family members other than husband or wife, usually to children. When the valentine-exchange cards made in school activities are included the figure goes up to 1 billion, and teachers become the people receiving the most valentines. The average valentine's spending has increased every year in the U.S, from $108 a person in 2010 to $131 in 2013.
The rise of Internet popularity at the turn of the millennium is creating new traditions. Millions of people use, every year, digital means of creating and sending Valentine's Day greeting messages such as e-cards, love coupons or printable greeting cards. An estimated 15 million e-valentines were sent in 2010. Valentine's Day is considered by some to be a Hallmark holiday due to its commercialization.
Valentine's Day is a major source of economic activity, with total expenditures in 2017 topping $18.2 billion in 2017, or over $136 per person. This is an increase from $108 per person in 2010.
In the first part of the 21st century, the celebration of Valentine's Day in Iran has been harshly criticized by Islamic teachers who see the celebrations as opposed to Islamic culture. In 2011, the Iranian printing works owners' union issued a directive banning the printing and distribution of any goods promoting the holiday, including cards, gifts, and teddy bears. "Printing and producing any goods related to this day including posters, boxes and cards emblazoned with hearts or half-hearts, red roses and any activities promoting this day are banned ... Outlets that violate this will be legally dealt with", the union warned.
Valentine's Day has been strongly criticized from a postcolonial perspective by intellectuals from the Indian left. The holiday is regarded as a front for "Western imperialism", "neocolonialism", and "the exploitation of working classes through commercialism by multinational corporations". It is claimed that as a result of Valentine's Day, the working classes and rural poor become more disconnected socially, politically, and geographically from the hegemonic capitalist power structure. They also criticize mainstream media attacks on Indians opposed to Valentine's Day as a form of demonization that is designed and derived to further the Valentine's Day agenda. Right wing Hindu nationalists are also hostile. In February 2012, Subash Chouhan of the Bajrang Dal warned couples that "They cannot kiss or hug in public places. Our activists will beat them up". He said "We are not against love, but we criticize vulgar exhibition of love at public places".
Since the 19th century, handwritten notes have given way to mass-produced greeting cards. In the UK, just under half of the population spend money on their Valentines, and around £1.9 billion was spent in 2015 on cards, flowers, chocolates and other gifts. The mid-19th century Valentine's Day trade was a harbinger of further commercialized holidays in the U.S. to follow.
In 2016, local governing body of Peshwar officially banned the celebration of Valentine's Day in the city. The ban was also implemented in other cities such as Kohat by the local governments.
In 2016, local media reported that police had informed coffee shops and ice cream parlours in Tehran that they would be guilty of committing a crime if they encouraged "decadent Western culture through Valentine's Day rituals". Under Iran’s Islamic law, unmarried couples are not allowed to mingle. That is why each year the printing works owners’ union issues an instruction on the ban of Valentine's Day, imposed by Iranian authorities which denies them from selling gifts such as cards, and boxes with the symbols of hearts and red roses. Iran says it is cracking down on Valentine’s Day celebrations and shops engaging in them will be guilty of a crime. In recent years Iranian authorities have forbidden Valentine’s celebrations, calling the holiday a “decadent Western custom” and threatening shops and restaurants with prosecution if they sell Valentine’s Day gifts.
In the modern era, liturgically, the Anglican Church has a service for St. Valentine's Day (the Feast of St. Valentine), which includes the optional rite of the renewal of marriage vows. In 2016, Catholic Bishops of England and Wales established a novena prayer "to support single people seeking a spouse ahead of St Valentine's Day."
However, in 2017 and 2018, after a fatwa was widely circulated, the religious police did not prevent Muslims from celebrating the day.
In 2017, the Islamabad High Court banned Valentine's Day celebrations in public places in Pakistan.