The University of Debrecen is a university located in Debrecen, Hungary. It is the oldest continuously operating institution of higher education in Hungary (since 1538). Higher education began in Debrecen with the Calvinist College of Debrecen, which was founded in 1538. Over centuries of its existence it was one of the key institutions of higher education in Hungary. In the beginning of the 20th century the College was transformed into a university, and has a strong link and cooperation with the present Calvinist College's Debrecen Reformed Theological University. In 1908, the Calvinist Academy of Humanities was created, and in 1912, the Hungarian Royal University was founded. The university incorporated the theology, law, and arts faculties of the College and added a medical school. Teaching began in 1914 in the old Calvinist College buildings. In 1918, the first new medical school building was opened, and the original medical school campus was completed in 1927. In 1921, the university took the name of István Tisza, former prime minister of Hungary. In 1932 the university's main building was completed.