Alte Pinakothek, Munich When the English king Henry VIII also left Charles’ alliance, and the Emperor could no longer pay his armies without any lucrative conquests, there followed a mercenary revolt in March 1527. Emperor Charles V, painting (sketch) by Titian and his workshop assistant Lambert Sustris, 1548. The Vatican, the Duchy of Milan, the Republic of Venice and other northern Italian city states believed the Holy Roman Emperor had become too powerful and so joined the pro-French League of Cognac in 1526.

He laid claim to Milan and withdrew from the alliance with Charles V. After the devastating defeat of the French army at the Battle of Bicocca in 1522, Pope Clement, who had previously sided with the Spanish-Imperial troops, saw an opportunity. For six years, Spain, which was under Charles V’s rule, and France under François I, had been battling for control of northern Italy. The unrestrained looting and pillaging by the mainly Lutheran mercenaries of Charles V – the elected but still uncrowned Holy Roman Emperor – was a long time in the making. The Getty Center The Sack of Rome that took place on was to be a dark day. Pope Clement VII in a painting by Sebastiano del Piombo, circa 1531. The escape was successful: the guards and the pope reached Castel Sant’Angelo unscathed. Forty-two of the escapees were Swiss guards, under the command of Lieutenant Herkules Göldli from Zurich, and one was Pope Clement VII himself. Forty-three men hurried breathlessly through the torch-lit barrel vault, of Rome’s ‘Passetto di Borgo’ – an 800-metre-long secret passage connecting the Vatican and Castel Sant’Angelo, which from the outside looks like an ordinary wall.

The darkest surrender