KU Leuven will celebrate its 600th anniversary in 2025, making it one of Europe’s oldest universities. Our institution has the double honour of being the oldest university in the Low Countries and the oldest extant Catholic university in the world. The University that is now known as KU Leuven was founded with the papal bull ‘Sapientie immarcessibilis’. This was issued by Pope Martin V on 9 December 1425 after the city of Leuven had requested permission for the foundation of the University with the support of John IV, Duke of Brabant, and the city’s clergy.

The university of Leuven initially comprised four faculties: humanities (‘Artes’), canon law, civil law, and medicine. In 1432, the Pope gave permission to add theology to that list.

Ever since it was founded, the University has had its headquarters in what is now known as the University Hall. Initially meant to serve as the cloth makers’ hall of Leuven, this stately building was constructed in 1317. In 1425, it became the beating heart of the University, with offices for the Rector and Vice Rectors, and it was home to various University services. For several centuries, the University Hall also comprised lecture halls and meeting rooms for the faculties. The University court had its seat there as well.

Great minds

A little over a century after it was founded, the University accommodated about 2,000 students, of whom more than 200 came from abroad. The presence of several great minds, one being humanist philosopher Desiderius Erasmus, was certainly part of the appeal. Erasmus spent several years in Leuven and actively contributed to the development of the University. Well known is his involvement in the printing and publishing of Thomas More’s controversial Utopia, which appeared in Leuven in 1516. Erasmus also founded the Collegium Trilingue, which was built on the Leuven fish market (Vismarkt, in Dutch) in 1517. This centre of humanistic activities is at the basis of the development of critical research.

Drawing from the input of intellectuals and inquisitive minds from all over Europe, Leuven continued to devote itself to the practice of science, albeit with ups and downs, depending on the intellectual climate of the time.

Sixteenth-century Leuven was a haven for scholars from all across the continent. Big names such as the aforementioned Erasmus, anatomist Vesalius, cartographer Mercator, mathematician Gemma Frisius, pedagogy scholar Vives and many others led the way. The university of Leuven was also a stronghold against the Reformation. Leuven remained loyal to the Catholic Church – without being a religious university, however. The University has always been a critical centre of learning, fostering a healthy amount of tension in its interaction with Church authorities.

In the seventeenth and eighteenth century, the university of Leuven continued to attract renowned scientists. One of them was physician Jozef Rega, who held the office of Rector several times. In 1738, he added a new wing to the University Hall that held the library until the fire of 1914. Rega also financed the Botanical Garden (1738), which later became property of the city, and the Anatomical Theatre (1744), the heart of the medical campus in Leuven. At the time of the Austrian Netherlands, physics started to emerge as a field of research, with a ‘lab’ created in the former Artes faculty building, now the M-Museum Leuven. In 1783, at the end of the Age of Enlightenment, chemist Jan Pieter Minckelers discovered the suitability of coal gas for lighting. But intensive and structurally embedded research would not be the norm in Leuven – or at most other universities, for that matter – for almost another century.

The University had a growing impact on the city landscape. The numerous colleges and pedagogieën, where the students lived and studied, were often built with the support of generous donors and dispersed throughout the city centre. Many of them have been preserved, although some have undergone major renovation.

New elan

Meanwhile, major political developments left their mark on what is now KU Leuven. Sometimes the University benefited from these developments; sometimes it had no choice but to bear the consequences. Under French rule, its Catholic reputation did not do the University any good: it was closed in 1797. Almost twenty years later, in 1817, King William I of the Netherlands reopened it as the State University of Leuven, which was meant to be impartial. On the initiative of the Belgian bishops it became a Catholic institution again in 1834.

Education at the nineteenth-century University was primarily aimed at a kind of advanced vocational training. Gradually, and especially at the end of the nineteenth century, the rapid developments in scientific research started having a growing impact on education. In 1889, the Institute of Philosophy was established with an eye to breathing new life into critical thinking, in line with the progress made in the natural sciences. The initiative was taken by Désiré-Joseph Mercier, a young professor who would later become cardinal. He understood that a modern university had to embrace the development of scientific research. The University continued emphasizing its roots in the humanities but also developed the other scientific domains. Suffice it to refer to the ground-breaking research of Professor Georges Lemaître, whose hypothesis of the expanding universe (1927) has contributed to the theory of general relativity and cosmology, and who may be considered the founding father of the Big Bang theory (1931).

Flemish and international

Even though the university of Leuven is located in Flanders, the main language of communication in the nineteenth century was French. It wasn’t until 1911, when the first lectures were taught in Dutch, that the Dutch language slowly started to become more important. Against the backdrop of the political turmoil of the late sixties, the university of Leuven was split into two independent sister universities: ‘Katholieke Universiteit Leuven’ (now KU Leuven) with Dutch as the official language, and the French-speaking ‘Université catholique de Louvain’ (UCL). The latter established itself on the brand-new campuses in Louvain-la-Neuve (in the Walloon provinces) and Woluwé (Brussels). Today, the two sister universities are on an excellent footing and collaborate in the areas of education, research and organization.

In 1968, Pieter De Somer became the first Rector of the independent University. The new University pursued scientific development with an international focus. Research boomed, and so did student numbers. It was time to expand, both in and around Leuven, with campuses for science and technology on the Arenberg estate in Heverlee and one for biomedical sciences on Gasthuisberg, where construction works for the new University Hospitals complex began in the 1980s.

In 2002, KU Leuven concluded an association agreement with fourteen Flemish university colleges. The agreement was part of the harmonization efforts that changed the course of the European higher education system with the Bologna declaration of 1999. The academic degree programmes offered by these university colleges have been fully integrated into KU Leuven since 2013. The University now offers degree programmes on campuses in eleven different cities.

Today, KU Leuven accommodates 50,000 students, spread across the various campuses in Leuven and elsewhere in Flanders. The University and University Hospitals Leuven each employ almost 10,000 people. For research, KU Leuven ranks among the world’s finest. KU Leuven has become a cosmopolitan institution in a rapidly changing urban environment. Its unique profile reconciles cutting-edge science with quality of life and openness to talent.