Florence was a centre of medieval European trade and finance and one of the wealthiest cities of that era. It is considered by many academics to have been the birthplace of the Renaissance, and has been called "the Athens of the Middle Ages". Its turbulent political history includes periods of rule by the powerful Medici family and numerous religious and republican revolutions. From 1865 to 1871 the city served as the capital of the Kingdom of Italy (established in 1861). The Florentine dialect forms the base of Standard Italian and it became the language of culture throughout Italy due to the prestige of the masterpieces by Dante Alighieri, Petrarch, Giovanni Boccaccio, Niccolò Machiavelli and Francesco Guicciardini.