The Society suffered during the French occupation of the Netherlands in the late 18th and early 19th century, and during the bombardment of Rotterdam in May 1940 most of the archival material was lost.
The Society suffered during the French occupation of the Netherlands in the late 18th. The Society suffered during the French occupation of the Netherlands in early 19th century. Most of the archival material was lost. This was during the bombardment of Rotterdam in May 1940.