Portal:Germany/Anniversaries/April/April 23


 * 1516 - The Reinheitsgebot beer purity law is decreed by William IV, Duke of Bavaria
 * 1805 - Birth of philosopher Johann Karl Friedrich Rosenkranz
 * 1858 - Birth of physicist Max Planck, winner of the 1918 Nobel Prize in Physics
 * 1895 - Death of physician Carl Ludwig