en 1340

1340 in various calendars
Gregorian calendar	1340; MCCCXL
Ab urbe condita	2093
Armenian calendar	789; ԹՎ ՉՁԹ
Assyrian calendar	6090
Balinese saka calendar	1261–1262
Bengali calendar	746–747
Berber calendar	2290
English Regnal year	13 Edw. 3 – 14 Edw. 3
Buddhist calendar	1884
Burmese calendar	702
Byzantine calendar	6848–6849
Chinese calendar	己卯年 (Earth Rabbit); 4037 or 3830; — to —; 庚辰年 (Metal Dragon); 4038 or 3831
Coptic calendar	1056–1057
Discordian calendar	2506
Ethiopian calendar	1332–1333
Hebrew calendar	5100–5101
Hindu calendars
- Vikram Samvat	1396–1397
- Shaka Samvat	1261–1262
- Kali Yuga	4440–4441
Holocene calendar	11340
Igbo calendar	340–341
Iranian calendar	718–719
Islamic calendar	740–741
Japanese calendar	Ryakuō 3; (暦応３年)
Javanese calendar	1252–1253
Julian calendar	1340; MCCCXL
Korean calendar	3673
Minguo calendar	572 before ROC; 民前572年
Nanakshahi calendar	−128
Thai solar calendar	1882–1883
Tibetan calendar	阴土兔年; (female Earth-Rabbit); 1466 or 1085 or 313; — to —; 阳金龙年; (male Iron-Dragon); 1467 or 1086 or 314

Millennium:	2nd millennium
Centuries:	13th century; 14th century ; 15th century;
Decades:	1320s; 1330s; 1340s ; 1350s; 1360s;
Years:	1337; 1338; 1339; 1340 ; 1341; 1342; 1343;

Events

January 26 – King Edward III of England declares himself King of France at Ghent, Flanders.
March 6 – Bohemian Crusade: The Church authorizes a military expedition against heretics.
April 8 – Marinid galleys, under the command of Muhammad ibn Ali al-Azafi, rout the Castellan fleet, off the coast of Algeciras.
April–July – Trapezuntine Civil War: An abortive uprising occurs against Irene Palaiologina of Trebizond, the first of a number of coups, revolts, and succession disputes.
June 7 – Rotterdam is officially declared a city.
June 24
- Hundred Years' War: Battle of Sluys – The English fleet, under the command of Edward III of England, battles the French fleet, under that of Admiral Hugues Quiéret and treasurer Nicolas Béhuchet, assisted by Genoese mercenary galleys under Egidio Bocanegra, on the Low Countries coast. The French fleet is virtually destroyed, and both of its commanders are killed.
- Valdemar IV of Denmark, son of deceased King Christopher II, is elected to the throne, following 8 years of interregnum.
July 26 – Hundred Years' War – Battle of Saint-Omer: The French defeat the English.
September 25 – Hundred Years' War: The temporary Truce of Espléchin is signed between England and France.^[1]
October 30 – Battle of Río Salado in Spain: The kings of Castile and Portugal defeat the Nasrid ruler of Granada and his Moroccan allies.

Europe has about 74 million inhabitants.
An epidemic in northern Italy is recorded by Augustine of Trent, in his Epistola astrologica.
The Monarchy of Japan reaches its 2,000 year anniversary (according to traditional starting dates).

March 5 – Cansignorio della Scala, Lord of Verona (d. 1375)
March 6 – John of Gaunt, 1st Duke of Lancaster (d. 1399)
August – Haakon VI, king of Norway 1355–1380 and of Sweden 1362–1364 (d. 1380)
October – Geert Groote, Dutch founder of the Brethren of the Common Life (d. 1384)
November 30 – John, Duke of Berry, son of John II of France (d. 1416)
date unknown
- Enguerrand VII, Lord of Coucy (d. 1397)
- John of Nepomuk, saint of Bohemia (d. 1393)
- Narayana Pandit, Indian mathematician (d. 1400)
probable
- Margaret Drummond, queen consort of Scotland (d. 1375)^[2]
- Philip van Artevelde, Flemish patriot (d. 1382)

^ Palmer, Alan; Palmer, Veronica (1992). The Chronology of British History. London: Century Ltd. pp. 102–104. ISBN 0-7126-5616-2.
^ "5 forgotten queens and princesses of Scotland". www.scotsman.com. Retrieved May 4, 2022.