1170 On this day in history birth of isabelle of Hainaut, queen of France (d. 1190)
1185 King Afonso II of Portugal (d. 1223) was born on this day in history.
1464 On April - 23 birth of johanna van Valois, Queen of France
1464 On April - 23 birth of robert Fayrfax, composer
1484 Julius Caesar Scaliger, Italy, scholar (On the Subtlety of Things) was born on this day in history.
1500 On this day in history birth of alexander Alesius, [Aless/Alane], System theologist/physician
1500 On this day in history birth of alexander Ales, Scottish theologian (d. 1565)
1516 On April - 23 birth of georg Fabricius, German poet, historian, and archaeologist (d. 1571)
0034 Death of Christ, crucified, according to Isaac Newton on April - 23.
0303 On this day in history death of george, knight/saint/patron of England, beheaded
0725 On this day in history death of wihtred, King of Kent
0871 On April - 23 ethelred I, king of Wessex/brother of Alfred the Great, dies
0990 Ekkehart II, [Palatinus], monk to St-Gallen/poet, dies on this day in history.
0997 On April - 23 vojtech "Adalbert" of Prague, 2nd bishop of Prague/apostle, dies at 40
1014 Brian Boru, king of Ireland, dies in battle at 87 on this day in history.
1016 On this day in history aethelbred II "the Unready", king of England (979-1016), dies