Natalija Konstantinović was a Princess of Montenegro, as the wife of Prince Mirko Petrović-Njegoš. By virtue of marriage she was member of the House of Petrović-Njegoš, ruling family of the Kingdom of Montenegro. The couple had five sons; however, two died in early childhood. They divorced in 1917, a year after the royal family was forced to flee the kingdom. She was the granddaughter of Princess Anka Obrenović of Serbia, member of the ill-fated House of Obrenović. Her husband was promised the Serbian crown in the event of King Alexander I dying childless; however, the crown went to Prince Peter Karađorđević, her husband's brother in law, following Alexander's assassination in 1903.

Prince Mirko Dimitri Petrović-Njegoš of Montenegro was born in Cetinje, the second son of King Nicholas I of Montenegro and Milena Vukotić. Prince Mirko predeceased his father and his elder brother Crown Prince Danilo.