- May 8 Greek War of Independence: Greeks defeat the Turks in Gravia
- May 12 The first major battle of the Greek War of Independence against the Turks occurs in Valtetsi
- May 30 James Boyd patents Rubber Fire Hose
- May 31 Cathedral of Assumption of Blessed Virgin Mary, 1st US Catholic cathedral, is dedicated in Baltimore, designed by Benjamin Henry Latrobe
Authors
Dictators
Explorers
Outlaws
Queens
Spies