1756 (MDCCLVI in Roman numerals) is an 18th century leap year.
Palazzo Ricasoli Firidolfi, in Florence, was bought by Maria Lucrezia Firidolfi (the previous owner was Gian Francesco Ridolfi).
The ancient facade of the Mantua Cathedral was demolished and the current one was erected at the same time.
January - June
March 17: St. Patrick's Day, of Irish origin, is celebrated in New York for the first time (at the Crown and Thistle Tavern).
12 April - Seven Years' War: France invades Menorca, then under British control.
May 15 - Seven Years 'War: The Seven Years' War formally begins in the United Kingdom when the United Kingdom declares war on France.
May 20 - Seven Years' War - Battle of Menorca: the British fleet commanded by John Byng is beaten by the French one commanded by Roland-Michel Barrin de La Galissonière.
May 28 - Seven Years' War: the British garrison in Menorca surrenders to the French.
June 25: Maritime Society is founded in London (the oldest maritime charity in the world. Archived October 8, 2006 in Archive.is.).
July - December
July 30: Bartolomeo Rastrelli presents the Catherine Palace to Empress Elizabeth I and her court.
August 14 - Seven Years' War - French and Indian War: Fort Oswego is taken by the French.
29 August - Seven Years' War: Frederick II of Prussia invades Saxony, starting the war on the European continent.
1st October - Seven Years' War - Battle of Lobositz: Frederick defeats the Austrian army commanded by Marshal Maximilian Ulysses Count Browne.
December - Seven Years War - French Indian War: militias from the Royal Colony of North Carolina build a fort on the western provinces to protect them from invasions by natives, allied with the French. Fort Dobbs was named in honor of the colony's governor, Arthur Dobbs, who convinced the North Carolina government to finance the project quickly.
Wolfgang Amadeus Mozart, Christian name Joannes Chrysostomus Wolfgangus Theophilus Sigismundus Mozart (Salzburg, January 27, 1756 - Vienna, December 5, 1791
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