The strain of dual careers and constant separation from his wife led to an extended breach in his marriage. The couple began separation proceedings in 1916, and separation by mutual consent was granted in 1919. In the period 1916–22, Nielsen often lived on Funen retreating to the Damgaard and Fuglsang estates, or worked as a conductor in Gothenburg. The period was one of creative crisis for Nielsen which, coinciding with World War I, would strongly influence his Fourth (1914–16) and Fifth symphonies (1921–22), arguably his greatest works according to Fanning. The composer was particularly upset in the 1920s when his long-standing Danish publisher Wilhelm Hansen was unable to undertake publication of many of his major works, including "Aladdin" and "Pan and Syrinx".