Workers' councils, known as "rady delegatów robotniczych" (councils of workers' delegates) or simply "rady robotnicze" (workers' councils), were formed in Poland at various times throughout the 20th century. The first known examples occurred during the Revolution in the Kingdom of Poland (1905–1907), part of the 1905 Russian Revolution, wherein workers in Congress Poland took control of factories and sometimes even entire towns until tsarist authorities quelled the rebellion using police and military forces; alongside Central Russia and Latvia, Congress Poland was one of the most active centres of the 1905 of revolution.