 Giertz wrote more than 600 works but is known in the English-speaking world mostly for his book "The Hammer of God".Giertz was born in Räpplinge on Öland, an island off the east coast of Sweden.His father, Knut Harald Giertz, was a well-known doctor, the son of John Bernard and Augusta Giertz; for two years he taught surgery at Uppsala University.