DRIVING DOWN A fog-bound autostrada in northern Italy one freezing day in January 1999, Mary Hollingsworth took a snap decision to visit the Este archives at Modena. Ippolito d'Este (second son of Alfonso I d'Este, Duke of Ferrara, and Lucrezia Borgia), a prince of the Church and builder of the magnificent Villa d'Este outside Rome, had been in the back of her mind as a subject for some time. Not many people would have chosen to visit the archives in Modena in January but Mary Hollingsworth found what she was looking for: thousands of letters and hundreds of account books revealing Ippolito and his life in intimate detail. Again, not many people would have found account books in sixteenth-century Italian script of absorbing interest, nor would they have been capable of understanding them, but Hollingsworth is a cultural historian with an accountant's training. To her, the Este archive represented the raw material of history.

The life of a Renaissance cardinal had very little to do with religion, but everything to do with money and conspicuous consumerism. A cardinal - particularly one with aristocratic connections like Ippolito - was expected to display magnificence and head a huge household. Many cardinals ruined themselves with their extravagance: