May 26: Jerusalem Day in Israel ( 2006); Independence Day in Guyana ( 1966) and Georgia ( 1918); Mother's Day in Poland; National Sorry Day in Australia.
- 1805 - Napoléon Bonaparte was crowned King of Italy at the Duomo di Milano with the Iron Crown of Lombardy.
- 1896 - The Dow Jones Industrial Average was first published by Charles Dow as a stock market index.
- 1918 - The Democratic Republic of Georgia was proclaimed.
- 1972 – Richard Nixon and Leonid Brezhnev signed the Anti-Ballistic Missile Treaty in Moscow, concluding SALT I.
- 1986 – The European Community adopted the European flag (pictured).