WEBOctober 15: The day after October 4, 1582, is designated October 15 by order of Pope Gregory XIII. June 21: Japanese warlord Oda Nobunaga assassinated in "incident at Honnō-ji". 1582 ( MDLXXXII) was a common year starting on Monday (link will display the full calendar) in the Julian calendar, and a common year starting on Friday ...