A year ago, Archbishop Carlo Maria Viganò was a retired diplomat who was little known beyond the limited world of Vaticanologists. He had reached the senior position of apostolic nuncio to the United States in October 2011, but his retirement in 2016 would normally have signalled an end to his influence.

On August 25, 2018, however, Archbishop Viganò issued an astonishing declaration which gained him a notoriety for which his previous career contained no precedent. An 11-page document, released simultaneously to news outlets in Italy and the US, made claims which sent shock waves through the worldwide Church.