Complex sentence: The Principality of Montenegro (/ Knjaževina Crna Gora) was a former realm in Southeastern Europe that existed from 13 March 1852 to 28 August 1910.
Split into simpler sentences: The Principality of Montenegro (Serbian: Књажевина Црнa Горa, "Knjaževina Crna Gora"), was a former realm in Southeastern Europe. It existed from 13 March 1852 to 28 August 1910.