He participated in the bombing of the Amsterdam public records office to hinder the Nazi German effort to identify Dutch Jews and others wanted by the Gestapo.

Willem Johan Cornelis Arondéus was born in Naarden, as the youngest son of an Amsterdam fuel trader.

The poems and stories he had written in the 1920s went unpublished, but in the year 1938 he published two novels, Het Uilenhuis ('The Owls House') and In de bloeiende Ramenas ('In the Blossoming Winter Radish'), both illustrated with designs by Arondéus himself.

Two years later, Figuren en problemen der monumentale schilderkunst in Nederland ('Figures and Problems of Monumental Painting in the Netherlands') was published, again with designs by the author.

[1][2] Arondéus pleaded guilty and took the full blame, which may be why two young doctors were spared from execution and given custodial sentences instead.

Before his execution, Arondéus made a point of ensuring the public would be aware that he and two other men in the group, Bakker and Brouwer, were gay, asking either a friend or his lawyer (accounts vary) to "Tell people that homosexuals are not cowards.

[2] In 2023 the English actor and broadcaster Stephen Fry made a Channel 4 documentary about Arondéus and Belinfante's wartime resistance activity, Willem & Frieda.

[9] In National Geographic's biographical World War II drama miniseries A Small Light, Willem Arondéus is played by Sean Hart.