The chancel and the chapels around it make up the oldest part of the church. In the Middle Ages the church had 34 altars and ten chapels, erected in honour of patron saints. After the church became Protestant in 1578, chapels were used as a carpenters’ workshop, a storage space for the gravestone carver, and a boiler house and kitchen for the sexton.
The oldest chapel is the Eggertkapel to the right of the chancel, erected after the death of Willem Eggert, who had commissioned the building of the church, by his son Jan.
Sculptors carved the corbels under the windows into shapes such as trolls, female figures, and portly monks grasping jugs of wine. The windows of two chapels display 36 family coats of arms. One of them belonged to Frans Banning Cocq, the central figure in Rembrandt’s Night Watch.