July 15

The Franciscan theologian Bonaventure died during the Second Council of Lyon, where he had helped negotiate a short-lived church union.

French soldiers rebuilding a fort near Rosetta uncovered a trilingual stele whose Greek, Demotic, and hieroglyphic texts would later open the door to reading ancient Egyptian.

Isaac Newton's Philosophiae Naturalis Principia Mathematica, setting out his laws of motion and universal gravitation, was completed and distributed in the summer of 1687.