The Montenegrin–Ottoman War, also known in Montenegro as the Great War, was fought between the Principality of Montenegro and the Ottoman Empire between 1876 and 1878. The war ended with Montenegrin victory and Ottoman defeat in the larger Russo-Turkish War of 1877–1878. Six major and 27 smaller battles were fought, among which was the crucial Battle of Vučji Do.

A rebellion in nearby Herzegovina sparked a series of rebellions and uprisings against the Ottomans in Europe. Montenegro and Serbia agreed to declare a war on the Ottomans on 18 June 1876. The Montenegrins allied themselves with Herzegovians. One battle that was crucial to Montenegro's victory in the war was the Battle of Vučji Do. In 1877, Montenegrins fought heavy battles along the borders of Herzegovina and Albania. Prince Nicholas took the initiative and counterattacked the Ottoman forces that were coming from the north, south and west. He conquered Nikšić (24 September 1877), Bar (10 January 1878), Ulcinj (20 January 1878), Grmožur (26 January 1878) and Vranjina and Lesendro (30 January 1878).

The war ended when the Ottomans signed a truce with the Montenegrins at Edirne on 13 January 1878. The advancement of Russian forces toward the Ottomans forced the Ottomans to sign a peace treaty on 3 March 1878, recognising the independence of Montenegro, as well as Romania and Serbia, and also increased Montenegro's territory from 4,405 km² to 9,475 km². Montenegro also gained the towns of Nikšić, Kolašin, Spuž, Podgorica, Žabljak, Bar, as well as access to the sea.