The city of Erfurt was founded in 792 as a bishopric by St. Boniface. By the 16th century, Erfurt was known as the "German Rome" because of the number of churches and monasteries. Even to this day, as you travel toward the historic city center, you are impressed by the number of steeples on the skyline. When Luther was there, Erfurt had 21 parish churches, four collegiate churches, and 11 monastery churches. It was also home to the second oldest university in Germany, founded in 1392. Luther enrolled as a student at Erfurt University in 1501. On July 17, 1505, Luther entered the "Black Cloister," entering a door on the Comthur Alley in Erfurt. The doorway is visible to this day.