Year 1347 (MCCCXLVII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.
February 2 – The Byzantine civil war between John VI Kantakouzenos and the regency for John V Palaiologos ends with Kantakouzenos entering Constantinople.
April – The Knights Hospitaller defeat a Turkish fleet and sink 100 ships off Imbros.
The agreement reorganizing the Byzantine Empire's affairs is finalized as Anna of Savoy's son John V Palaiologos marries Kantakouzenos' 15-year-old daughter Helena.
Genoese ships fleeing the Black Death plague in Kaffa stop in Constantinople, contaminating the city.
May 20 – Cola di Rienzo, a Roman commoner, declares himself Emperor of Rome in response to years of baronial power-struggles.
August 2 – The Islamic Bahmani Kingdom is established on the Indian subcontinent.
September – In the Hundred Years' War, the English win the city of Calais.
September 1 – The Black Death reaches the French city of Marseilles.
October – Ships arrive to the southern Italian Peninsula carrying people affected by with the Black Plague onboard.
Pope Clement VI unites several of Rome's upper-class nobility, who drive Cola di Rienzo out of the city
King Phillip of France meets with the Estates General to ask for funds to further the war effort against the English
November 1 – Black Death spreads to Aix-en-Provence in France
December – Plague hits the island of Majorca
December 25 – First cases of the plague recorded in the city of Split in Croatia.
December 27 – to fund the military operations in Corsica, the Republic of Genoa had to borrow at 20% from an association of creditors known as the Compera nuova acquisitionis Corsicæ.
The Charles University in Prague is founded (this or the next year).
The Mamluke Empire was hit by the plague in the autumn. Baghdad was hit in the same year.
After years of resistance against the Delhi Sultan Muhammud bin Tughluq, the Bahmani Kingdom, a Muslim Sultanate in Deccan, was established on August 3, when King Ala-ud-din Hasan Bahman Shah was crowned in a mosque in Daulatabad. Later in the year, the Kingdom's capital was moved from Daulatabad to the more central Gulbarga. Southeast Asia suffered a drought which dried up an important river which ran through the capital city of the Kingdom of Ayodhya, forcing the King to move the capital to a new location on the Lop Buri River.
Eastern and Scandinavian
On 2 February the Byzantine Empire's civil war between John VI Kantakouzenos and the regency ended with John VI entering Constantinople. On 8 February, an agreement was concluded with the empress Anna of Savoy, whereby he and John V Palaiologos would rule jointly. The agreement was finalized in May when John V married Kantakouzenos' 15-year-old daughter. The war had come at a high cost economically and territorially, and much of the Empire was in need of rebuilding. To make matters worse, in May Genoese ships fleeing the Black Death in Kaffa stopped in Constantinople. The plague soon spread from their ships to the city. By autumn, the epidemic had spread throughout the Balkans, possibly through contact with Venetian ports along the Adriatic Sea. Specific cases were recorded in the northern Balkans on 25 December, in the city of Split.
On 20 May Cola di Rienzo, a Roman commoner, declared himself Emperor of Rome in front of a huge crowd in response to what had been several years of power struggles among the upper-class barony. Pope Clement VI, along with several of Rome's upper-class nobility, united to drive him out of the city in November. In October, Genoese ships arrived in southern Italy with the Black Plague, beginning the spread of the disease in the region. Jews were first accused of ritual murders in Poland in 1347. Casimir III of Poland issues Poland's first codified collection of laws after the diet of Wiślica. Separate laws are codified for greater and lesser Poland.
In the continuing Hundred Years' War, the English won the city of Calais in a treaty signed in September. In a meeting with the Estates General in November, the French King Phillip was told that in the recent war efforts they had "lost all and gained nothing." Phillip, however, was granted a portion of the money he requested and was able to continue his war effort. The English King Edward offered Calais a package of economic boosts which would make Calais the key city connecting England with France economically. Edward returned to England at that height of his popularity and power and for six months celebrated his successes with others in the English nobility. Although the Kingdom's funds were largely pushed towards the war, building projects among the more wealthy continued, with, for example, the completion of Pembroke College in this year.
The French city of Marseilles recognized the plague on 1 September and by 1 November it had spread to Aix-en-Provence. The earliest recorded invasion of the plague into Spanish territory was in Majorca in December 1347, probably through commercial ships. 3 years of Plague began in England.February 6 – Dorothea of Montau, German hermitess and visionary (d. 1394)
February 27 – Alberto d'Este, Lord of Ferrara and Modena (d. 1393)
March 25 – Catherine of Siena, Italian saint (d. 1380)
March 31 – Frederick III, Duke of Austria, second son of Duke Albert II of Austria (d. 1362)
July 28 – Margherita of Durazzo, Queen consort of Charles III of Naples (d. 1412)
August 29 – John Hastings, 2nd Earl of Pembroke, English nobleman and soldier (d. 1375)
Eleanor of Arborea, ruler of Sardinia (d. 1404)
Elizabeth of Pomerania, fourth and final wife of Charles IV, Holy Roman Emperor (d. 1393)
Emperor Go-Kameyama, 99th Emperor of Japan (d. 1424)
Richardis of Schwerin, queen consort of Sweden (d. 1377)
February 2 – Thomas Bek, Bishop of Lincoln, was the bishop of Lincoln (b. 1282)
May 30 – John Darcy, 1st Baron Darcy de Knayth, English peer (b. 1290)
June – John de Warenne, 7th Earl of Surrey, English nobleman (b. 1286)
June 11 – Bartholomew of San Concordio, Italian Dominican canonist and man of letters (b. 1260)
October 11 – Louis IV, Holy Roman Emperor (b. 1282)
November – Richard de Pilmuir, bishop of Dunkeld
November 12 – John of Viktring, Austrian chronicler and political advisor in Carinthia (b. 1270–1280)
November 15 – James I of Urgell, Prince of Aragon (b. 1321)
Hazrat Shah Jalal, sufi saint of Bengal (b. 1271)
William of Ockham, English philosopher (b. 1288)
Blanca de La Cerda y Lara, Spanish noblewoman (b. 1317)
John de Egglescliffe, English bishop
Adam Murimuth, English ecclesiastic and chronicler (b. 1274)
Peter III of Arborea, Judge of Arborea
Lamberto II and Pandolfo da Polenta, brothers and lords of Ravenna and Cervia
Kokan Shiren, Japanese Rinzai Zen patriarch and celebrated Chinese poet (b. 1278)