1427

1427 (MCDXXVII) was a common year starting on Wednesday of the Julian calendar, the 1427th year of the Common Era (CE) and Anno Domini (AD) designations, the 427th year of the 2nd millennium, the 27th year of the 15th century, and the 8th year of the 1420s decade. As of the start of 1427, the Gregorian calendar was 9 days ahead of the Julian calendar, which was the dominant calendar of the time.

• August 4 – Hussite Wars: Battle of Tachov The Hussites decisively beat the crusader armies, ending the Fourth Anti-Hussite Crusade.
• August 17 – First band of Gypsies visits Paris, according to an account of the citizen of Paris.
• Lincoln College, a constituent college of the University of Oxford, is founded.
• Balsics rule of Montenegro comes to an end.
• Bhaktapur Royal Palace in Nepal is built by King Yaksa Malla.
• Gabriel V elected Patriarch of the Coptic Church for the second time.
• Minrekyansa becomes King of Ava (ancient Burma).
• Conflict of Druimnacour in Sutherland, Scotland.
• First witch hunts begin, in Switzerland.
• Celestine Order established in France.
• Celebration of Sant Jordi (Saint George) begins in Catalonia (he would later become its patron saint).
• Bremen is expelled from the Hanseatic League.
• Diogo de Silves, Portuguese navigator, discovers seven islands of the Azores archipelago.

• September 9 – Thomas de Ros, 10th Baron de Ros, English politician (died 1464)
• October 14 – Alesso Baldovinetti, Italian painter (died 1499)
• October 26 – Archduke Sigismund of Austria (died 1496)
• November 29 – Zhengtong Emperor of China (died 1464)
• November 30 – Casimir IV Jagiellon, King of Poland (died 1492)
• date unknown
  • Shen Zhou, Chinese painter (d. 1509)

• April 17 – John IV, Duke of Brabant (b. 1403)
• May 7 – Thomas la Warr, 5th Baron De La Warr, English churchman
• August 27 – Reginald West, 6th Baron De La Warr (born 1395)
• date unknown
  • Chimalpopoca, Aztec ruler of Tenochtitlán (born 1397)
  • Qu You, Chinese novelist (born 1341)
• probable
  • Jehuda Cresques, Catalan cartographer (born 1350)
  • Gentile da Fabriano, Italian painter