On 3 January 993, Pope John XV became the first pope to proclaim a person a saint from outside the diocese of Rome: on the petition of the German ruler, he had canonized Bishop Ulrich of Augsburg. Before that time, the popular "cults", or venerations, of saints had been local and spontaneous and were confirmed by the local bishop. Pope John XVIII subsequently permitted a cult of five Polish martyrs. Pope Benedict VIII later declared the Armenian hermit Simeon of Mantua to be a saint, but it was not until the pontificate of Pope Innocent III that the Popes reserved to themselves the exclusive authority to canonize saints, so that local bishops needed the confirmation of the Pope. Walter of Pontoise was the last person in Western Europe to be canonized by an authority other than the Pope: Hugh de Boves, the Archbishop of Rouen, canonized him in 1153. Thenceforth a decree of Pope Alexander III in 1170 reserved the prerogative of canonization to the Pope, insofar as the Latin Church was concerned.
Alban Butler published Lives of the Saints in 1756, including a total of 1,486 saints. The latest revision of this book, edited by Herbert Thurston and Donald Attwater, contains the lives of 2,565 saints. Robert Sarno, an official of the Dicastery for the Causes of Saints of the Holy See, expressed that it is impossible to give an exact number of saints.
A saint may be designated as a patron saint of a particular cause, profession, or locale, or invoked as a protector against specific illnesses or disasters, sometimes by popular custom and sometimes by official declarations of the church. Saints are not believed to have power of their own, but only that granted by God. Relics of saints are respected, or venerated, similar to the veneration of holy images and icons. The practice in past centuries of venerating relics of saints with the intention of obtaining healing from God through their intercession is taken from the early church. For example, an American deacon claimed in 2000 that John Henry Newman (then blessed) interceded with God to cure him of a physical illness. The deacon, Jack Sullivan, asserted that after addressing Newman he was cured of spinal stenosis in a matter of hours. In 2009, a panel of theologians concluded that Sullivan's recovery was the result of his prayer to Newman. According to the church, to be deemed a miracle, "a medical recovery must be instantaneous, not attributable to treatment, disappear for good."