Churches & Religion

Saint Sulpitius Church

Tradition has it that the first St Sulpitius Church was founded by Saint Remaclus in the seventh century. The place of prayer was probably built of wood and stood on the site of the current church. Later, a Roman church was established here. In 1312, the church wardens decided to replace this with a new and larger church building. This had to keep in step with the ruling power of Diest at the time and be erected in the new style, which was: Gothic.

Since in Brabant the Gothic style was still in its infancy, assistance was sought from French architects. For Diest, the French master builder, Pierre de Savoye, provided the design. Numerous elements in the construction refer to the scheme of French Gothic cathedrals. This is the case of the heavy supporting walls with adorning arch buttresses, which serve to absorb the lateral pressure of the high openwork walls. Construction at the site dragged on for two centuries. By the way, did you know that the tomb of Prince Philip William of Orange-Nassau is located in the presbytery (eastern part of the church chancel beyond the choir)? He was the oldest son of William the Silent (William I, Prince of Orange).


The space of the church building was gradually enlarged, starting with the chancel. Accordingly, a whole host of architects was involved in the execution, including Hendrik van Tienen (responsible for the magnificent southern facade), Sulpitius van Vorst, (the later master builder of Saint Peter's Church in Leuven) and Mattheus de Layens (master builder of Leuven town hall).

Mosterdpot (mustard pot, nickname for the Carillon Tower)

The long basilical building contains a Baroque carillon tower on the crossing. The combination of the rusty brown colour of ironstone with the white French stone of the tower give the church its own personal touch. In Lier, the lantern tower (or crossing/transept tower) is called ‘the pepper tin’, in Lokeren ‘the salt barrel’ and in Diest ‘the mustard pot’. Diest locals gave their nickname 'mosterdpotschijters' (little mustard pots) to the tower. Mustard pot here is the tiny top of the church tower, the highest point of a church. Exotic herbs were very expensive, so that ordinary people had to make do with cheap, homegrown mustard.

Patron Saints

The patron saints of the church and the city are Saint Sulpitius and Saint Dionysius. Two saints, respectively Bishop of Bourges and Bishop of Paris, who have been venerated in the French capital since time immemorial.





  • Grote Markt
  • From 1 may till 30 september: The Saint Sulpitius church is open every day, except on monday, from 13.00 till 17.00. From october till april: every first sunday of the month
  • Admission fee: free