Aakjær's notable novels, including "Bondens Søn" (""The Peasant's Son"") (1899) and "Vredens børn, et tyendes saga" (""Children of Wrath: A Hired Man's Saga"") (1904), reveal his staunch social commitment. The latter is a rural Danish answer to Upton Sinclair's "The Jungle" and in many ways caused the same effect but on a lesser scale. He also wrote "Hvor Bønder bor" (""Where Farmers Live"") (1908), "Arbejdets Glæde" (""The Joy of Work"") (1914), and "Jens Langkniv" (1915), about a Danish highwayman becoming a guerrilla fighter against the Germans in the 17th century. Many tales and short stories tell about the humble, bad life of farm boys and grooms and are written with a visceral anger and a fighting spirit. He also wrote some plays, such as "Livet paa Hegnsgaard", (""Life at the Hegn Farm"") (1907), and a biography on his predecessor, Steen Steensen Blicher.