The Sovereign Military Hospitaller Order of Saint John of Jerusalem of Rhodes and of Malta is one of the oldest and most venerable institutions in the Catholic Church. Established in the  eleventh century to care for pilgrims to the Holy Lands and to defend Christians during the Crusades, it has evolved into a major global humanitarian agency. In late 2016, a group of senior knights and their advisers became embroiled in an ugly public row with the Pope. It ended with Francis insisting on the resignation of the Grand Master and demanding a major reform of the order. A new leader, who will be given the task of pushing through these changes, is to be elected next month although the knights could renew the mandate of their current interim chief.

The dispute reveals many of the stresses and tensions inside the Church.