A condottiero was an Italian mercenary leader during the Renaissance era. Condottieri were bound by condotes, meaning "contracts". They were hired as mercenary generals to command armies for various nations. During the Italian Wars, the main nations of France, La Serenissima, Venice, Siena, Spain, the Holy Roman Empire, and Naples all hired condotierri as generals. Famous condotierri include Bartolomeo d'Alviano, Fabrizio and Prospero Colonna, Ercole II of Ferrara, Francisco Gonzaga, Fabio Orsini, Micheletto Attendolo, Mario Auditore, and Niccolò di Pitigliano.