[2] Danilo I Petrović-Njegoš was recognized as Sovereign Prince of Montenegro by Russia on 21 March 1852, and established succession by male primogeniture.

During World War I the Petrović Njegoš family were forced to flee the country in 1915 after the Army of Montenegro was overwhelmed by the troops of the Austro-Hungarian Empire.

[citation needed] The family gained the French citizenship as they made their home in France where Nikola I of Montenegro died in exile in 1921.

Growing up in France, Nicholas barely saw his father and knew very little about Montenegro or his family's history being raised and educated as a Frenchman.

[5] In 1967 while a student he visited Montenegro for the first time, upon showing his university ID card the staff bowed upon recognising the Petrović-Njegoš name.

[10] On 27 November 1976 in Trébeurden, Côtes-du-Nord, he married Francine Navarro (Casablanca, 27 January 1950 - Paris, 6 August 2008), fashion designer, daughter of Antoine Navarro (Melilla, 29 January 1922 - Marseille, 12 August 1989), who fought in the French Foreign Legion, and wife Rachel Wazana (Casablanca, 19 July 1929), of Moroccan Jewish descent, paternal granddaughter of Francisco Navarro and wife Carmela Padia and maternal granddaughter of Charles Wazana and wife Fanny.

[11] Together they raised a family at Les Lilas, France: He bears the Montenegrin Coat of Arms, which can be seen at the centre of the Flag of Montenegro.

[citation needed] The Constitution of 2007 maintained "the tradition" of King Nicholas I: the adopted Coat of Arms was a crowned silver eagle with the sara in one and the sceptre in the other claw, and charged on its breast was a red shield with the lion passant.