1675
Leibniz Invents Calculus
The German philosopher and mathematician Gottfried Wilhelm Leibniz, working independently of Newton, developed a calculus of infinitesimals with a notation so clear that it would become the European standard. Newton had done it earlier; Leibniz published first. The two men and their followers would feud bitterly for decades over priority.
King Philip's War Begins
Metacom, the Wampanoag sachem the English called King Philip, attacked the Plymouth settlement of Swansea after years of encroachment on his lands. The war that followed burned half the towns in New England to the ground and killed perhaps a tenth of the English colonists and a larger fraction of the Algonquian population.
Sikh Guru Tegh Bahadur Executed in Delhi
Mughal emperor Aurangzeb, demanding conversion to Islam, ordered the beheading of the ninth Sikh Guru, Tegh Bahadur, in Chandni Chowk. The Guru had refused to abandon his faith or the Kashmiri Brahmins he had sworn to protect. His martyrdom transformed Sikhism from a peaceful movement into a martial brotherhood under his son, Guru Gobind Singh.
Royal Observatory at Greenwich Founded
Charles II, advised that better astronomical tables would help the navy navigate, founded an observatory at Greenwich and appointed John Flamsteed the first Astronomer Royal at one hundred pounds a year. Flamsteed began a forty-year catalog of stars that would, in time, give the world its prime meridian and establish Greenwich as the zero point of global longitude.