Following the period of peace, which had lasted since 1739, Russia began to assert its expansionistic desires again in 1768. Under the pretext of pursuing fugitive Polish revolutionaries, Russian troops entered Balta an Ottoman-controlled city on the border of Bessarabia and massacred its citizens and burned the town to the ground. This action provoked the Ottoman Empire into the First Russo-Turkish War of 1768–1774. The Treaty of Küçük Kaynarca of 1774 ended the First Russo-Turkish War and allowed that the Christian citizens of the Ottoman-controlled Rumanian provinces of Wallachia and Moldavia would be allowed freedom to worship. Russia was made the guarantor of their right to Christian worship.