On March 22, 1621, Grotius managed to escape his lifelong prison sentence. Hidden in his book chest, he was carried out of the castle by unwitting soldiers and taken to Gorinchem. Once the chest had been delivered in Gorinchem, Grotius got out and, disguised as a mason, made his way to Paris, via Antwerp. A year later Grotius published a poem titled Silva ad Thuanum, in which he describes the escape and reveals that it was Maria who came up with the plan after noticing that the soldiers had stopped checking the book chest. Maria was not prosecuted for her role in Grotius’ escape and would soon follow her husband to Paris.
Hugo de Groot, Silva ad Thuanum, book, 1621 [THYSIA 1390-2]