Year 1387 (MCCCLXXXVII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.
January – Sigismund, the future Holy Roman Emperor and husband of Mary, Queen of Hungary, orders the murder of his mother-in-law, Elizabeta Kotromanic, and declares himself joint ruler of Hungary.
January 1 – Charles III ascends to the throne of Navarre after the death of his father, Charles II.
January 5 – John I succeeds his father, Peter IV, as King of Aragon and Valencia, and forms an alliance with France and Castile.
March 11 – The Battle of Castagnaro is fought between Verona and Padua: Padua, led by John Hawkwood, is victorious over Giovanni Ordelaffi of Verona.
June 2 – John Holland, a maternal half-brother of Richard II of England, is created Earl of Huntingdon.
August 22 – Olaf, King of Norway and Denmark and claimant to the throne of Sweden, dies. The vacant thrones come under the regency of his mother Margaret I of Denmark, who will soon become Queen in her own right.
December 19 – Battle of Radcot Bridge: Forces loyal to Richard II of England are defeated by a group of rebellious barons known as the Lords Appellant. Richard II is imprisoned until he agrees to replace all the councillors in his court.
Timur conquers the Muzaffarid Empire in central Persia and appoints three puppet rulers.
Khan Tokhtamysh of the Golden Horde invades the Timurid Empire but has to soon after withdraw due to heavy snow.
Magha II succeeds his brother, Musa II, as Mansa of the Mali Empire.
July 6 – Queen Blanche I of Navarre (d. 1441)
date unknown – Henriette, Countess of Montbéliard, regent of Württemberg (d. 1444)
January – Elizabeth of Bosnia, regent of Hungary
January 1 – King Charles II of Navarre (b. 1332)
January 6 – Peter IV of Aragon (b. 1319)
July 20 – Robert IV of Artois, Count of Eu (poisoned) (b. 1356)
July 22 – Frans Ackerman, Flemish statesman (b. 1330)
August 23 – King Olaf IV of Norway/Olaf II of Denmark (b. 1370)
date unknown
Richard Óg Burke, second Clanricarde
Sir David Hanmer, judge, father-in-law of Owain Glyndŵr
1387 Wikipedia (Text) CC BY-SA