Richard the 2nd is Deposed
King Richard the 2nd of England has taken the oaths of 82 knights and 125 esquires (probably well-born non-nobles) and gained effective control over Parliament. The King then sentences Henry the 4th (John of Gaunt's son) to banishment for placing legal limits on the King. Then John of Gaunt drops dead... allowing Henry to become the Duke of Lancaster, a very powerful position. The King revokes Henry's inheritance and then leaves for Ireland on a military adventure. Unfortunately for the King, Henry is not well guarded and circles back to take the King hostage in the Tower of London. According to the record Richard will "voluntarily abdicate" and Parliament will find that perfectly acceptable. No problem whatsoever. Henry will take over as King. Eventually someone will try to rescue Richard from the Tower but that will fail. Another group will try to murder him. As a rule, having an extra king around is dangerous to stability. Richard will die early next year at the age of 33. Henry will be blamed but there is a very long list of suspects. He probably didn't do it. He didn't have to.    
Accusations of Host Desecration
A Christian woman living in Posen, Poland is accused of stealing three wafers or hosts representing the Holy Eucharist. In religious terms that means she stole the body of Christ as represented by the wafers.(There is no easy way to say that without some technical disagreement so try to roll with it.) She then gave the hosts to the Jews of Posen who were then accused of desecrating the hosts by stabbing them repeatedly. Reportedly the hosts bled. All the Jews in question, the rabbi of the town and the Christian woman were burned to death on the spot... slowly. Accusations of Host Desecration are just beginning. The accusations will die out some time after the Protestant Reformation gets going in 1517. It will be an ugly time in between.    
Ottoman Empire: Threatening Tamerlane and Constantinople
Sultan Bayezid the 1st enters Syria to threaten the Mamluks. The Mamluks were once slaves of a greater Egyptian kingdom that was destroyed by the Mongols. Now these former slaves have a kingdom of their own that stretches from Egypt to Syria and is threatened by the Ottoman Turks. But the Ottoman Sultan has become too powerful too fast. His army consist of units from various vassal states and slaves he has captured along the way. They haven't learned to fight as a cohesive unit yet, and Tamerlane's army is on its way to Aleppo, Syria. It has had plenty of experience as a fighting unit. Sultan Bayezid is in big trouble and he doesn't know it yet. 
This Year on Wikipedia
Year 1399, Wikipedia.
- Cantor, Norman F., Imagining the Law: Common Law and the Foundations of the American Legal System, New York: HarperCollins, 1997. p. 42. (BOOK)
- Jones, Michael. (and other editors) The New Cambridge Medieval History Volume 6: c.1300-c.1415. Cambridge University Press. 2000. ISBN: 978-0521362900. p. 320-3. (BOOK)
- Richard II of England - Wikipedia, 2014 [last update]
- Henry IV of England - Wikipedia, 2014 [last update]
- HOST, DESECRATION OF - JewishEncyclopedia.com, 2014 [last update]
- Kieval, Hillel J. Blood Libels and Host Desecration Accusations. YIVO Encyclopedia of Jews in Eastern Europe. 2011-Jan-06. (IMAGE) caption (partial)="Three Holy Hosts, Which the Jews Stabbed with Knives in Poznań in 1399, (Poznań, 1772)."
- 1399, from Jewish History. (TIMELINE) quote="(Posen) - A Christian woman was accused of stealing 3 hosts and giving them to Jews for the purpose of desecrating them. Under the instigation of the local Archbishop, the Rabbi, thirteen members of the community and the woman were all tortured and burned alive slowly. The community was forced to pay a special tax each year for more until the 18th century."
- Richert, Scott P., What Is the Eucharist?, About.com, 2014 [last update]
- Transubstantiation - Wikipedia, 2014 [last update]
- Holt, P. M., Lambton, Ann K., Lewis, Bernard. (editors) Cambridge History of Islam Volume 1, The Central Islamic Lands, The. Cambridge University Press. 1970. ISBN: 978-0521075671. pp. 278-279. (BOOK)
- Byzantium (Eastern Roman Empire) - Wikipedia, 2014 [last update]