On 16 May 1614, Maeslandsluys was separated from Maesland by the counts of Holland and renamed Maassluis. This separation may have been religiously motivated: Maassluis was predominantly Protestant and Maasland Catholic. In 1624 the defense wall was demolished to make way for the Great Church, started in 1629. Construction stopped for five years because privateers from Dunkirk raided fishing boats from Maassluis, throwing their crew overboard. It was finished in 1639. On 4 December 1732, the Garrels Organ was inaugurated. Built from 1730 to 1732 by Rudolf Garrels, a pupil of Arp Schnitger, it was a gift by Govert van Wijn, ship-owner from Maassluis.