Old St Peter's Basilica in Rome stood for over eleven centuries until it was demolished to make room for today's church on the same Vatican site. Its last eyewitness, Maffeo Vegio, explained to the Roman hierarchy how revival of the papacy, whose prestige after the exile to Avignon had been diminished, was inseparable from a renewed awareness of the primacy of Peter's Church. To make his case, Vegio wrote a history founded on credible written and...