Prince Adalbert was born on 14 July 1884 as the third son of the then Prince Wilhelm of Prussia and his first wife, Princess Augusta Victoria of Schleswig-Holstein. He was born in the Marmorpalais of Potsdam in the Province of Brandenburg , where his parents resided until his father acceded to the throne as Emperor Wilhelm II in 1888.
Prince Friedrich Karl Nikolaus of Prussia (20 March 1828 – 15 June 1885) was the son of Prince Charles of Prussia (1801–1883) and his wife, Princess Marie of Saxe-Weimar-Eisenach (1808–1877). Prince Friedrich Karl was a grandson of King Frederick William III of Prussia and a nephew of Frederick William IV and William I.