The Royal Sigismund Bell (Polish: Królewski Dzwon Zygmunt or Dzwon Zygmunta) is the largest of the five bells hanging in the Sigismund Tower of the Wawel Cathedral in the Polish city of Kraków. It was cast in 1520 by Hans Behem and named after its patron, Sigismund I, King of Poland and Grand Duke of Lithuania, who commissioned it. The bell weighs almost 13 tonnes (28 thousand pounds) and requires 12 bell-ringers to swing it.