Verona | Peter Pan | Peter Gabriel | Peter Jackson | Peter | Saint Peter | Peter Paul Rubens | Peter Sellers | Peter the Great | Blue Peter | Peter Frampton | Peter Greenaway | Peter Brook | Peter Lorre | Peter Ustinov | St. Peter's Basilica | Peter Kropotkin | St. Peter | Peter Fonda | Peter Kay | Peter David | Peter Mandelson | Peter O'Toole | Peter Allen | Lord Peter Wimsey | Peter Sellars | Peter Schreier | Peter, Paul and Mary | Peter Davison | Peter Singer |
The bull was issued in the wake of the murder of the papal inquisitor of Lombardy, St. Peter of Verona, who was killed by a conspiracy of Cathar sympathizers on 6 April 1252.