Prince Mirko Dimitri PetroviÃÂ-Njegoà ¡ of Montenegro (; 17 April 1879 â 2 March 1918) was born in Cetinje, the second son of King Nicholas I of Montenegro and Milena VukotiÃÂ. Prince Mirko predeceased his father and his elder brother Crown Prince Danilo.
On 25 July 1902 in Cetinje, Prince Mirko married Natalija Konstantinovià(10 October 1882 in Trieste â 21 August 1950 in Paris), daughter of Colonel Alexander Konstantinovià(1848âÂÂ1914) and Milena Opuiàfrom Trieste. She was the granddaughter of Aleksandar Konstantinovià(1803âÂÂ1858) and Princess Anka Obrenovià(1 April 1821 â murdered, Belgrade, 10 June 1868), daughter of Jevrem Obrenovià(1790 â 20 September 1856), younger brother of Miloà ¡ ObrenoviàI, Prince of Serbia (1816), and Tomanija Bogicevià(1796 â 13 June 1881).
The couple had five sons before divorcing in October 1917:
Their eldest surviving son Prince Michael of Montenegro, succeeded Mirko in the Montenegrin royal succession and would become head of the House of PetroviÃÂ-Njegoà ¡ and pretender to the Montenegrin throne.
As Prince Mirko's wife was the granddaughter of Anka (Anna) ObrenoviÃÂ, a member of the Serbian House of ObrenoviÃÂ, it was agreed with the Serbian Government that Prince Mirko would be proclaimed Crown Prince of Serbia in the event that the marriage of King Alexander and Draga Maà ¡in was childless.
Following the assassination of Alexander and Draga in 1903, the resulting conferral of the crown was given to Peter KaraÃÂorÃÂeviÃÂ, his brother-in-law. In 1911 he joined the Black Hand "Unity or Death" secret society which sought the unification of all Serbs in the Balkans, especially those under Austria-Hungary.
Mirko divorced his wife in 1917. He moved from Paris to Vienna, where he died in 1918. Following his death, his ten-year-old son Prince Michael of Montenegro was raised in Paris by his mother and the residual members of the exiled Montenegrin Royal Family. In 1921 following the death of Mirko's father and shortly afterwards by the renouncement of the defunct throne by former Crown Prince Danilo, the thirteen-year-old Prince Michael of Montenegro became the head of the PetroviÃÂ-Njegoà ¡ house, albeit initially under a pretense regency.