📅 Today in HistorySeptember 16

Pope Honorius I is posthumously excommunicated by the Sixth Ecumenical Council.

Owain Glyndŵr is declared Prince of Wales by his followers.

Pilgrims set sail for Virginia from Plymouth, England in the Mayflower.

James Francis Edward Stuart, sometimes called the "Old Pretender", becomes the Jacobite claimant to the thrones of England and Scotland on the death of his father, James II.

In Campo Maior, Portugal, a storm hits the Armory and a violent explosion ensues, killing two-thirds of its inhabitants.

American Revolutionary War: The Battle of Harlem Heights is fought.

American Revolutionary War: The Franco-American Siege of Savannah begins.

With the Grito de Dolores, Father Miguel Hidalgo begins Mexico's fight for independence from Spain.

French physicist Augustin-Jean Fresnel, in a "note" read to the Academy of Sciences, reports a direct refraction experiment verifying David Brewster's hypothesis that photoelasticity (as it is now known) is stress-induced birefringence.

Robert College, in Istanbul, the first American educational institution outside the United States, is founded by Christopher Robert, an American philanthropist.