During the Reformation period historical research was becoming more sophisticated, as exemplified by the recently rediscovered scholarship of an astonishing Catholic historian who embodied an open and imaginative approach to the new historiography

In 2007 Pope Benedict XVI tweaked the rules for papal elections. He mandated that “a majority vote of two thirds of the cardinal electors present is always necessary for the valid election of a Roman Pontiff”. His predecessors Paul VI and John Paul II had decreed that under certain circumstances – if a conclave had too many unsuccessful ballots – an absolute majority could be enough to break the deadlock.

It was a conservative move. Since the earliest times, the way in which the head of the Church has been chosen has undergone changes. Benedict was confirming a decree from more than eight centuries earlier. In 1179, Pope Alexander III and the Third Lateran Council had decided that a majority of two-thirds of cardinals’ votes would be needed for an election to be valid. Such a majority minimised the danger of an election being contested by losing parties, and the system proved robust enough to endure for nearly 800 years.

Bishops of Rome have been elected for nearly two millennia, but historians only began to investigate what had really happened in these elections during the religious conflict sparked by the Reformation. At that time, the past became a confessional battleground: Protestants and Catholics each used history to strengthen their religious identity and affirm their superiority over the other.