The Castellammarese War was a bloody power struggle for control of the Italian-American Mafia between partisans of Joe "The Boss" Masseria and those of Salvatore Maranzano. It was so called because Maranzano was based in Castellammare del Golfo, Sicily. Maranzano's faction won, and he declared himself capo di tutti capi ("boss of all bosses"), the undisputed leader of the entire Mafia. However, he was soon murdered in turn by a faction of young upstarts led by Lucky Luciano, who established a power-sharing arrangement called "The Commission," a group of five Mafia families of equal stature, to avoid such wars in the future.