Because of these incessant wars, the growth of Ukmergė suffered many setbacks. Jews began to settle in the city in the late 17th century, and built a synagogue and a cemetery.[5] In the years 1711–1712, the bubonic plague swept through the town and wreaked havoc upon its population. In 1792, by the initiative of the city's representative in the Great Sejm, Józef Dominik Kossakowski, King Stanisław August Poniatowski renewed the town's municipal rights and gave it its current coat of arms.