Year 1320 (MCCCXX) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar.
January 20 – Duke Wladyslaw Lokietek becomes king of Poland.
April 6 – The Scots reaffirm their independence by signing the Declaration of Arbroath.
Ghiyas al-Din Tughlaq founds the Tughlaq dynasty of the Delhi Sultanate.
The Venetian Arsenal is rebuilt as the Arsenal Nuovo.
The Second Shepherds' Crusade begins.
Dante's Quaestio de Aqua et Terra is published.
In England many horses die of a disease called "Ffarsine".
The Byzantine governor in the Morea, Andronikos Asen, captures the Frankish castles of Akova, Karytaina and St. George, securing control over Arcadia and Cynuria.
April 8 – King Peter I of Portugal (d. 1367)
date unknown
Blanka of Namur, queen consort of Sweden (d. 1363)
Chen Youliang, founder of the Great Han regime (d. 1363)
John Hawkwood, English mercenary (d. 1394)
Iolo Goch, Welsh poet (d. 1398)
Shams al-Dīn Abū Abd Allāh al-Khalīlī, Arab astronomer (d. 1380)
Lalleshwari, Hindu poet (d. 1392)
Louis of Taranto (d. 1362)
Michael Panaretos, chronicler of Trebizond (d. 1390)
Nissim of Gerona, talmudist and authority in Jewish law (d. 1380)
Otto, Duke of Brunswick-Grubenhagen (d. 1398)
Rudolph, Duke of Lorraine (d. 1346)
Ukhaantu Khan, Emperor Huizong of Yuan, emperor of the Yuan Dynasty (d. 1370)
William of Wykeham, Bishop of Winchester (d. 1404)
probable
Bertrand du Guesclin, Breton knight (d. 1380)
King Valdemar IV of Denmark (d. 1375)
John Wycliffe, English reformer (d. 1384)
approximate
Turisanus, Florentine physician
January 12 – John Dalderby, Bishop of Lincoln
January 21 – Árni Helgason, Icelandic bishop (b. c. 1260)
February 7 – Jan Muskata, Bishop of Kraków (b. 1250)
March 1 – Ayurbarwada Buyantu Khan, Emperor Renzong of Yuan (b. 1286)
May 29 – Pope John VIII of Alexandria, Coptic pope
July 20 – King Oshin of Armenia (b. 1282)
October 12 – Michael IX Palaiologos, Byzantine co-emperor (b. 1277)
October 31 – Ricold of Monte Croce, Italian Dominican missionary (b. 1242)
date unknown
Blessed Margaret of Castello, patron of the poor, crippled, and unwanted (b. 1287)
Qutb ud din Mubarak Shah, last Khilji ruler of India
Radulphus Brito, French grammarian
Filippo Tesauro, Italian painter (b. 1260)
Yasa'ur, Chagatai prince
probable – Geoffrey of Paris, French chronicler
1320 Wikipedia (Text) CC BY-SA