January – Henry IV of England stops the Epiphany Rising and kills the Earls of Kent, Huntingdon and Salisbury and the Baron le Despencer, because they tried to have Richard II made as king.
February – Henry Percy (Hotspur) leads English army into Scotland.
February 14 – Richard II of England dies in Pontefract Castle but we don't know what killed him. King Henry IV might have ordered people to starve him to death.
March 23 – Five-year-old Trần Thiếu Đế is forced to stop being the ruler of Đại Việt (modern-day Vietnam) and give the throne to his maternal grandfather Hồ Quý Ly. This was the end of the Trần Dynasty after 175 years and the start of the Hồ Dynasty. Hồ Quý Ly changes the country's name to Đại Ngu.
May – Frederick I, Duke of Brunswick-Lüneburg tries to take over from Wenceslaus, King of the Romans. However, Frederick is murdered shortly after.
August
The English capture the city of Edinburgh in Scotland but do not capture Edinburgh Castle.
The princes of the German states vote that Wenceslaus is not King of the Romans because he did a bad job as king and because of his mental illnesses.
August 21 – Rupert, Count Palatine of the Rhine, is elected as King of the Romans.
September 16 – Owain Glyndŵr is made Prince of Wales by the Welsh, and he starts attacking English castles in north-east Wales.
November – Sack of Aleppo (1400) during Timur's conquest of Syria.
December – Manuel II Palaiologos becomes the only Byzantine Emperor ever to visit England.
Date unknown
Timur wins against the Ottoman Empire and the Mamluk Sultanate of Egypt. Timur captures the city of Damascus what is today Syria. Timur's army kills many of the city's people.
Timur conquers the Empire of the Black Sheep Turkomans, in present-day Azerbaijan, and the Jalayirid Dynasty in present-day Iraq. Black Sheep ruler Qara Yusuf and Jalayirid Sultan Ahmad run away and go to live with the Ottoman Sultan Bayezid I.
King Jeongjong of Joseon stops being king because he is afraid his younger brother, Taejong, will attack him. Taejong becomes king.