Halmstadgruppen is credited with being "the Swedish Surrealists". Hugo Palmskölds "Halmstadgruppen" is a brief introduction to them, in essence just an essay with some very nice illustrations. The members were inspired by modernist painting, turned towards surrealism in the thirties, moved on from it in the forties, and the group dissolved in the fifties.
Members of the group were Sven Jonson, Waldemar Lorentzon, Stellan Mörner, Axel Olson, Erik Olson and Esaias Thorén. They received a bit of criticism during their existence, like for being too "nice" and too "understandable": "You're finding proselytes among the dullest bourgeoisie! Freud must be ashamed of your painting!", as one critic put it. Later, in the late eighties, dyspeptic art critic Peter Cornell complained that a retrospective exhibition showed the group not to be sufficiently obscene and blasphemous to be called "surrealists" – in other words, for not sufficiently sharing his depressive-aggressive worldview.
Me, I think they created a lot of nice pictures (which is good in itself), some of which seem to be expressing fear and anxiety for the coming war – like the cover picture above, by Esaias Thorén, 1938: "The game has begun". But they also IMO suffer a bit from the same problem as a lot of surrealist painting: great technical skill exerted to tell what is basically usually a pretty simple, if amusing, joke – and MAD Magazine has done it funnier and cheaper.
Worth the read, and Halmstadgruppen's pictures are indeed worth looking at.