In the period of peace which followed Nikola carried out a series of military, administrative and educational reforms. The country was embroiled in a series of wars with the Ottoman Empire between 1862 and 1878. In 1867 he met the emperor Napoleon III at Paris, and in 1868 he undertook a journey to Russia, where he received an affectionate welcome from the tsar, Alexander II. He afterwards visited the courts of Berlin and Vienna. His efforts to enlist the sympathies of the Russian imperial family produced important results for Montenegro; considerable subsidies were granted by the tsar and tsaritsa for educational and other purposes, and supplies of arms and ammunition were sent to Cetinje. In 1871 Prince Dolgorukov arrived at Montenegro on a special mission from the tsar, and distributed large sums of money among the people. In 1869 Prince Nikola, whose authority was now firmly established, succeeded in preventing the impetuous highlanders from aiding the Krivosians in their revolt against the Austrian government; similarly in 1897 he checked the martial excitement caused by the outbreak of the Greco-Turkish War.