I can't really write about the Borgia family -- as I did yesterday and as I am about to do again -- without deploying my favorite quotation from The Third Man. Restraint in this matter would do grave violence to my nature. Harry Lime, the worst racketeer in occupied Vienna, tells an old friend who has gone to a good deal of trouble to track him down, "Don't be so gloomy. After all it's not that awful. Like the fella says, in Italy for 30 years under the Borgias they had warfare, terror, murder, and bloodshed, but they produced Michelangelo, Leonardo da Vinci, and the Renaissance. In Switzerland they had brotherly love, they had 500 years of democracy and peace, and what did that produce? The cuckoo clock." What were the 30 years of Borgian dominance Harry had in mind? I suppose you might start the clock running in 1481, when Ludovico Sforza took power in the duchy of Milan. The fates of the Borgia and Sforza families were closely intertwined (anot...