The sky was an immaculate blue, and a strong September sun warmed the pilgrims squeezing into St Peter’s Square, burnishing the droplets from its two fountains into a liquid gold. Pope Francis could not have chosen a more beautiful day for the canonisation of Mother Teresa.

Around the Vatican the sense of occasion had been building up for days, with the streets packed with the faithful, from groups of excited Sisters in their distinctive white and blue from the Missionaries of Charity, beaming from ear to ear, to monks talking busily on their mobile phones.