Midsummer or Midsommar (Swedish: [ˈmɪ̌ˌsɔmːar] or [ˈmǐːdˌsɔmːar]) is a celebration of the season of summer, taking place on or near the date of the summer solstice in the Northern Hemisphere, the longest day of the year. The name midsummer mainly refers to summer solstice festivals of European origin. These cultures traditionally regard it as the middle of summer, with the season beginning on May Day. Although the summer solstice falls on 20, 21 or 22 June in the Northern Hemisphere, it was traditionally reckoned to fall on 23–24 June in much of Europe. These dates were Christianized as Saint John's Eve and Saint John's Day. It is usually celebrated with outdoor gatherings that include bonfires, maypole dancing and feasting.
There is evidence that the summer solstice has been culturally important since the Neolithic era, with many ancient monuments throughout Eurasia and the Americas aligned with sunrise or sunset on the summer solstice.
In the Julian calendar used in the ancient Roman world, the date of the summer solstice was 24 June, and Marcus Terentius Varro wrote in the 1st century BC that the Romans saw this as the middle of summer. In the city of Rome, it was the festival of the goddess Fors Fortuna. People thronged the River Tiber and rowed in boats to the temples of Fortuna; "after undisclosed rituals they rowed back, garlanded and inebriated".
The Julian calendar had a flaw in that the solstices and equinoxes gradually fell on earlier dates. At the First Council of Nicaea (325), the Christian Church set the date of the spring equinox to 21 March on the Julian calendar, for the purpose of calculating Easter. This also brought the date of the summer solstice forward to 20 June.
The name 'midsummer' is attested in Old English as midsumor, which meant the summer solstice. It was seen as the middle of summer in Anglo-Saxon England, with the season beginning in early May. Some Anglo-Saxon calendars place midsummer on 24 June while others place it on 20 June. Saint John's Day on 24 June was called middes sumeres mæssedæg or middesumores mæsse (Midsummer's Mass-day).
In England, 24 June continued to be called Midsummer Day and was one of the quarter days of the English calendar. Elsewhere in northern Europe, midsummer and the solstice were traditionally reckoned as the night of 23–24 June.
Sandra Billington says there is no evidence that the pre-Christian Germanic peoples celebrated the summer solstice.
The historian Ronald Hutton says that the "lighting of festive fires upon Saint John's Eve is first recorded as a popular custom by Jean Belethus, a theologian at the University of Paris, in the early twelfth century", but is undoubtedly much older. In England, the earliest reference to this custom occurs in the 13th century AD, in the Liber Memorandum of the parish church at Barnwell in the Nene Valley, which stated that parish youth would gather on the day to light fires, sing songs and play games. A Christian monk of Lilleshall Abbey, in the same century, wrote:
In the worship of St John, men waken at even, and maken three manner of fires: one is clean bones and no wood, and is called a bonfire; another is of clean wood and no bones, and is called a wakefire, for men sitteth and wake by it; the third is made of bones and wood, and is called St John's Fire.
The 13th-century monk of Winchcomb, Gloucestershire, who compiled a book of sermons for Christian feast days, recorded how St John's Eve was celebrated in his time:
Let us speak of the revels which are accustomed to be made on St. John's Eve, of which there are three kinds. On St. John's Eve in certain regions the boys collect bones and certain other rubbish, and burn them, and therefrom a smoke is produced on the air. They also make brands and go about the fields with the brands. Thirdly, the wheel which they roll. ... The wheel is rolled to signify that the sun then rises to the highest point of its circle and at once turns back
Saint John's Fires, explained the monk of Winchcombe, were to drive away dragons, which were abroad on St John's Eve, poisoning springs and wells. A Christian interpretation of midsummer fires is that they are "an emblem of St. John the Baptist, who was 'a burning and shining light,' and the preparer of the way of Christ." The fires were also believed to repel witches and evil spirits.
On St John's Day in 1333, Petrarch watched women at Cologne rinsing their hands and arms in the Rhine "so that the threatening calamities of the coming year might be washed away by bathing in the river."
In 1482, German Franciscan friar Paul Walther provided an early documentation of the Albanian traditional practice of lighting fires (zjarre) on Saint John's eve.
In the 16th century AD, English historian John Stow described the celebration of Midsummer:
the wealthier sort also before their doors near to the said bonfires would set out tables on the vigils furnished with sweet bread and good drink, and on the festival days with meats and drinks plentifully, whereunto they would invite their neighbours and passengers also to sit, and to be merry with them in great familiarity, praising God for his benefits bestowed on them. These were called bonfires as well of good amity amongst neighbours that, being before at controversy, were there by the labour of others reconciled, and made of bitter enemies, loving friends, as also for the birtue that a great fire hat to purge the infection of the air. On the vigil of St John Baptist and St Peter and Paul the Apostles, every man's door being shadowed with green birch, long fennel, St John's Wort, Orpin, white lillies and such like, garnished upon with garlands of beautiful flowers, had also lamps of glass, with oil burinin in them all night, some hung branches of iron curiously wrought, containing hundreds of lamps lit at once, which made goodly show.
Saint John's Day is also a popular day for infant baptisms and in the 19th century, "baptisms of children who had died 'pagans' were acted out". In Sweden, young people visited holy springs as "a reminder of how John the Baptist baptised Christ in the River Jordan."
The early Christian Church designated 24 June as the feast day of the early Christian martyr St John the Baptist, and the observance of St John's Day begins the evening before, known as Saint John's Eve. These are commemorated by many Christian denominations, such as the Roman Catholic Church, Lutheran Churches, and Anglican Communion, as well as by freemasonry. In Sweden, Midsummer is such an important festivity that there have been proposals to celebrate the National Day of Sweden then, instead of on 6 June. There and in Finland, Estonia, Latvia and Lithuania, Midsummer is a public holiday. In Denmark and Norway, it may also be referred to as St. Hans Day.