After the Partitions of Poland and Napoleonic Wars, from 1815 the town was part of so-called Congress Poland within the Russian Partition of Poland. During a protest in Warsaw on 27 February 1861, Russian soldiers had fired on the gathered Poles, killing five, among them Marcel Karczewski, a landowner from Sieradz. In April, Złoczew nobility, common people, and Jews threw out the pro-Russian mayor Paweł Kużawski and his clerk. This event helped contribute to the January Uprising (1863–64) in and around Złoczew.