The history of Heidelberg University starts from its founding in 1386.
Founding
Around 1400, the city of Heidelberg had approximately 3,000 inhabitants, but the Great Schism in 1378, which split European Christendom into two hostile groups made it possible for this relatively small city to get its own university.
The Great Schism was initiated by the election of two popes after the death of Pope Gregory XI in the same year. One successor resided in Avignon (elected by the French) and the other in Rome (elected by the Italian cardinals). The German secular and spiritual leaders voiced their support for the successor in Rome, which had far-reaching consequences for the German students and teachers in Paris: they lost their stipends and had to leave.
Rupert I recognized the opportunity and initiated talks with the Curia, which ultimately led to the creation of the papal bull for the foundation of a university. After having received on October 23, 1385, the permission from pope Urban VI to create a school of general studies (), the final decision to found the university was taken on June 26, 1386, at the behest of Rupert I, Count Palatine of the Rhine. As specified in the papal charter, the university was modelled after University of Paris and included four faculties: philosophy, theology, jurisprudence, and medicine.
On October 18, 1386, a special Pontifical High Mass in the Heiliggeistkirche commemorated the opening of the doors of the university. On October 19, 1386, the first lecture was held, making Heidelberg the oldest university in Germany. In November 1386, Marsilius of Inghen was elected first rector of the university. As a motto for the seal, he chose semper apertus—i.e., "the book of learning is always open."
The university grew up quickly and in March 1390, 185 students were enrolled at the university
Early development
The newly created university acted from the outset as an intellectual center for theology and jurisprudence scholars from throughout the Holy Roman Empire. Nominalism had been prevalent from the time of Marsilius until after 1406, when Jerome of Prague, the friend of John Hus, introduced realism at Heidelberg, on which account he was expelled by the faculty. Six years later, the teachings of John Wycliffe were also condemned. Between 1414 and 1418, several distinguished professors of Heidelberg University took part in the Council of Constance and acted as counselors for Louis III, who attended this council as representative of the emperor and chief magistrate of the realm, and had John Hus executed as a heretic. In 1432, the university, pursuant to papal and imperial requests, sent two delegates to the Council of Basle who faithfully supported the legitimate pope.
The transition from scholastic to humanistic culture was effected by the chancellor and bishop Johann von Dalberg in the late 15th century. Humanism was represented at Heidelberg University particularly by the founder of the older German Humanistic School Rudolph Agricola, Conrad Celtes, Jakob Wimpfeling, and Johann Reuchlin. Æneas Silvius Piccolomini was chancellor of the university in his capacity of provost of Worms, and later always favored it with his friendship and good-will as Pope Pius II. In 1482, Pope Sixtus IV permitted laymen and married men to be appointed professors in the ordinary of medicine through a papal dispensation. In 1553, Pope Julius III sanctioned the allotment of ecclesiastical benefice to secular professors.
Martin Luther's disputation at Heidelberg in April 1518 made a lasting impact, and his adherents among the masters and scholars soon became leading Reformationists in Southwest Germany. With the Palatinate's turn to the Reformed faith, Otto Henry, Elector Palatine, converted the university into a Calvinist institution. In 1563, the Heidelberg Catechism was created under collaboration of members of the university's divinity school. As the 16th century was passing, the late humanism stepped beside Calvinism as a predominant school of thought; and figures like Paul Schede, Jan Gruter, Martin Opitz, and Matthäus Merian taught at the university. It attracted scholars from all over the continent and developed into a cultural and academic center. However, with the beginning of the Thirty Years' War in 1618, the intellectual and fiscal wealth of the university declined. In 1622, the then-world-famous Bibliotheca Palatina (the library of the university) was stolen from the University Cathedral and taken to Rome. The reconstruction efforts thereafter were defeated by the troops of King Louis XIV, who destroyed Heidelberg in 1693 almost completely.