Exactly fifty years ago, the heads of the Coptic Orthodox and Roman Catholic Churches signed a historic Christological agreement, putting an end to a 1,500-year old theological controversy and ushering in a new era of Coptic-Catholic relations. To mark the occasion, Pope Tawadros II, the head of the Coptic Orthodox Church, is in Rome this week. On Wednesday, at Pope Francis’ General Audience, he addressed the faithful gathered in St Peter’s Square – the first time the head of another Church has