UCLouvain (or Université catholique de Louvain [ynivɛʁsite katɔlik də luvɛ̃], French for Catholic University of Louvain, officially in English the University of Louvain) is Belgium's largest French-speaking university and one of the oldest in Europe (originally established in 1425). It is located in Louvain-la-Neuve, which was expressly built to house the university, and has smaller campuses in Brussels, Charleroi, Mons, Tournai and Namur. Since September 2018, the university uses the branding UCLouvain, replacing the acronym UCL, following a merger with Saint-Louis University, Brussels.
The original University of Louvain (Universitas Lovaniensis) was founded at the centre of the historic town of Leuven (or Louvain) in 1425, making it the first university in Belgium and the Low Countries, and abolished by law in 1797. This university was the centre of Baianism, Jansenism and Febronianism in Europe. A new university, the State University of Louvain, was founded in 1817 and abolished by the law in 1835. A new catholic university was founded in Mechlin in 1834, the Catholic University of Mechlin and moved to Leuven in 1835 that is frequently, but controversially, identified as a continuation of the older institution. In 1968 the Catholic University of Leuven split into the Dutch-language Katholieke Universiteit Leuven, which stayed in Leuven, and the French-language Université catholique de Louvain, which moved to Louvain-la-Neuve in Wallonia, 30 km southeast of Brussels. Since the 15th century, Leuven/Louvain, as it is still often called, has been a major contributor to the development of Catholic theology.