Battles for Plav and Gusinje
The Battles for Plav and Gusinje were armed conflicts between the Principality of Montenegro and the League of Prizren (supported by the Ottoman Empire) that broke out following the decision of the Congress of Berlin (1878) that the territories of Plav and Gusinje (part of former Scutari Vilayet) be ceded to Montenegro. The conflicts took place in this territory between 9 October 1879 and 8 January 1880.
Source: Wikipedia — Battles for Plav and Gusinje (CC BY-SA 4.0)