During the first years of the war he sold the complete stock but as he could only publish new books illegally, he joined the underground newspaper Vrij Nederland.
After the war he sold most of the activities of Daame started the literary magazine Maatstaf and published quite successfully poetry in paperback (Ooievaarpockets).
The younger Bakker's tenure was marked by conflict; he himself had little knowledge of literature and kept the company afloat by publishing a number of non-literary books.
[4] Prometheus/Bert Bakker became one of the largest literary publishers in the Netherlands, publishing best-selling authors such as Connie Palmen, Maria Stahlie, Tim Krabbé, Hafid Bouazza, and Martin Bril,[4] besides prominent historians and politicians such as Frits van Oostrom, Wouter Bos[2] and Wijnand Duyvendak.
Both were bought back by founder Mai Spijkers in 2007, making Uitgeverij Prometheus an independent publishing company with Bert Bakker as an imprint.