1351

January–December

• January 14 - Edward III of England institutes the Treason Act of 1351, defining treason in English law. It is currently one of the earliest statues still in force under English law.
• March 26 - War of the Breton Succession - Combat of the Thirty: Thirty chosen knights each, from the Kingdoms of France and England, fight to determine who will rule the Duchy of Brittany; a Franco-Breton victory is assured by the squire Guillaume de Montauban.
• April 8 - Hundred Years' War: At the Battle of Taillebourg the French are defeated by the English.
• May 1 - Zürich joins the Swiss Confederation.

  Date unknown

• King Ramathibodi I ascends the throne in Ayutthaya. He begins to propagate Theravada Buddhism as the state religion.
• King Gongmin ascends the throne in Goryeo.
• Emperor Go-Kōgon of Japan succeeds Emperor Sukō, making them the third and fourth of the Northern Ashikaga Pretenders, respectively.
• The Statute of Laborers is enacted by the Parliament of England, to deal with a labor shortage caused by the Black Death.
• Vantaa, Finland is first mentioned.
• Firuz Tughlaq succeeds Mohammad Tughlaq, as Sultan of Delhi.
• The Mongolian-run Yuan dynasty of China is permanently weakened by an uprising, known as the Red Turban Rebellion.
• The Samma Dynasty in Sindh breaks away from the Delhi Sultanate.
• The Turks cross the Dardanelles into Europe for the first time.