He was born in
Schwerin, the eldest child of the reigning Grand Duke of Mecklenburg-Schwerin,
Frederick Francis IV, and his wife
Princess Alexandra of Hanover, a daughter of
Crown Prince Ernest Augustus of Hanover (a first-cousin once removed of
Queen Victoria) and
Princess Thyra of Denmark, the youngest daughter of
King Christian IX of Denmark. Following the defeat of the
German Empire in
World War I, his father abdicated on 14 November 1918. He did not succeed to the throne, as the Grand Duchy was replaced with the
Free State of Mecklenburg-Schwerin. Upon the
promulgation of the
Weimar Constitution on 11 August 1919, titles of sovereigns such as emperor/empress, king/queen, grand duke/grand duchess, etc. were abolished. However, former titles shared and inherited by all members of the family were retained but incorporated into the surname. He therefore became known as Friedrich Franz
Herzog von Mecklenburg-Schwerin (or
Friedrich Franz, Duke of Mecklenburg-Schwerin)
de facto since the establishment of the Free State of Mecklenburg-Schwerin. ==Post monarchy==