Births on May 31

Andrew Grima, Anglo-Italian jewellery designer (d. 2007)

Andrew Grima (31 May 1921 – 26 December 2007) was an Anglo-Italian designer who became known as the doyen of modern jewellery design in Britain.

15 Feb

Helsinki
Kingdom of Romania establishes its legation in Helsinki.
20 Mar

Versailles Treaty
The Upper Silesia plebiscite was a plebiscite mandated by the Versailles Treaty to determine a section of the border between Weimar Germany and Poland.
11 Jul

William Howard Taft
Former President of the United States William Howard Taft is sworn in as 10th Chief Justice of the U.S. Supreme Court, becoming the only person ever to hold both offices.
29 Oct

Sacco and Vanzetti
United States: Second trial of Sacco and Vanzetti in Boston, Massachusetts.
11 Nov

Arlington National Cemetery
The Tomb of the Unknowns is dedicated by US President Warren G. Harding at Arlington National Cemetery.