Kalisz, the capital of a government (area, 4390 sq. m.; pop. in 1897, 846,334) of the same name in Russian Poland, lies on the frontier river, the Prosna, 132 miles WSW. of Warsaw, and has manufactures of cloth. The Kalisia of Ptolemy, it is one of the oldest towns of Poland; in its vicinity numerous relics of antiquity have been discovered, and many ancient burial-mounds exist.
Pop. (1892) 18,804. Two battles have been fought here: on 29th October 1706 King Augustus of Poland routed the Swedes, and on 13th February 1813 the Russians defeated the French and Saxons. Here, too, was signed on 28th February 1813 the treaty of alliance between Prussia and Russia.