December 14, 872: Pope Adrian (or Hadrian) II dies. Adrian twice refused the papacy (in 855 and 858) before reluctantly accepting in 867. Weak and vacillating, he sought support from, of all people, the antipope Anastasius.
December 14, 1363: French ecclesiastical statesman and writer Jean Gerson is born. Eager to end the Great Schism of 1378-1414, he was influential in calling the Council of Pisa and the Council of Constance (which eventually ended the dual papacy). In defense of the Council of Pisa, Gerson wrote a tract promoting counciliar theory—the idea that a council can supersede the pope.
December 14, 1591: Spanish poet John of the Cross, one of the greatest Christian mystics, dies. His "Dark Night of the Soul" is one of the era's best known religious poems, and his treatises have profoundly influenced both Catholic and Protestant thought.
December 14, 1853: Illinois Institute is begun by Wesleyan abolitionists. The school became Wheaton College after its president, Jonathan Blanchard, asked local landowner Warren Wheaton for a large property donation, offering to name the school after him and "save [his] heirs the expense of a good monument.