for his monks (approximate date). World Global environmental cooling occurs, due either to a comet impact or volcanic eruption in Central America, evidenced by global tree ring growth diminution.Baillie, M.G.L. (2007). Tree-Rings Indicate Global Environmental Downturns that could have been Caused by Comet Debris, Chap. 5 in Bobrowsky, Peter T. and Hans Rickman (eds.), Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach, Springer-Verlag, Berlin. , pp. 105–122. Recent evidence from Swiss ice core points to volcanic eruptions in Iceland. Historical evidence records this earlier as the Extreme weather events of 535–536. Births Authari, king of the Lombards (approximate date) Columbanus, Irish missionary (or 543) Galswintha, Neustrian queen, married to Chilperic I (d. 568) Garibald I, duke of Bavaria (d. 591) Pope Gregory I (the Great) (d. 604) John of Biclaro, Visigoth chronicler (approximate date) Myrddin Wyllt, Welsh legend (approximate date) Deaths Dignāga, Buddhist founder of Indian logic Dionysius Exiguus (approximate date) Fridolin of Säckingen Irish missionary Vedast, Frankish bishop Vitiges, king of the Ostrogoths Yifu, empress of Western Wei (b. 510) Yujiulü, empress of Western Wei (b. 525) References