1,701 years ago, Constantine the Great and co-emperor Valerius Licinius signed the Edict of Milan, proclaiming religious tolerance throughout the Roman Empire.
Also on this date, in 1525, Martin Luther, a priest, married Katharina von Bora, a nun, against the celibacy rule decreed by the Roman Catholic Church.
In 1774, Rhode Island became the first British colony in the Americas to prohibit the importation of slaves.
Grover Cleveland had a large portion of his jaw removed, for cancer, during a surgery on a boat in international waters, in 1893. The operation was not officially revealed to the U.S. public until nine years after the president’s death.