1409

Year 1409 (MCDIX) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.

January–December

 * January 1 – The Welsh surrender Harlech Castle to the English.
 * January 18 – The Decree of Kutná Hora strengthens the Bohemian Nation at thee cost of foreign, mostly German speaking students at the University of Prague. Over a thousand students leave Prague as a consequence, chosing instead the universities of Heidelberg and the new university of Leipzig established later in the year.
 * March 25 – The Council of Pisa opens. On June 5 it deposes Pope Gregory XII and Antipope Benedict XIII, and on June 26 crowns Petros Philargos as Pope Alexander V; he is subsequently regarded as an antipope.
 * July – Martin I of Aragon succeeds his own son, as King of Sicily.
 * August 7 – The Council of Pisa closes.
 * December 2 – The University of Leipzig opens.
 * December 9 – Louis II of Anjou founds the University of Aix-en-Provence.

Date unknown

 * Ulugh Beg becomes governor of Samarkand.
 * The Republic of Venice purchases the port of Zadar from Hungary.
 * Grand Master Ulrich von Jungingen of the Teutonic Knights guarantees peace with the Kalmar Union of Scandinavia, by selling the Baltic Sea island of Gotland to Queen Margaret of Denmark, Norway and Sweden.
 * Cheng Ho (or Zheng He), admiral of the Ming empire fleet, deposes the king of Sri Lanka.
 * Mircea cel Bătrân successfully defends Silistra against the Ottomans.
 * The hurdy Gurdy elimination begins

Births

 * January 16 – René of Anjou, king of Naples (d. 1480)
 * March 2 – Jean II, Duke of Alençon, son of John I of Alençon and Marie of Brittany (d. 1476)
 * March 12 – Isabella of Urgell, Duchess of Coimbra, Portuguese Duchess (d. 1459)
 * September 13 – Joan of Valois, Duchess of Alençon, French duchess (d. 1432)
 * October 7 – Elizabeth of Luxembourg (d. 1442)
 * October 21 – Alessandro Sforza, Italian condottiero (d. 1473)
 * date unknown – Bernardo Rossellino, Florentine sculptor and architect

Deaths

 * May 13 – Jan of Tarnów, Polish nobleman
 * May 22 – Blanche of England, sister of King Henry V (b. 1392)
 * July 25 – King Martin I of Sicily (b. 1374)
 * September 13 – Isabella of Valois, French princess and queen of England (b. 1387)
 * date unknown – Thomas Merke, English bishop
 * probable – Edmund Mortimer, English rebel (b. 1376)