He was crowned in the Sistine Chapel 3rd March 1878, and at once began a reform of the papal household on austere and economic lines which found little favour with the entourage of the former pope.
The cappa of the Lateran basilica worn by the canons of Westminster cathedral, or the almuce worn, by concession of Pope Pius IX., by the members of the Sistine choir.
Here he composed a large number of motets and sacred pieces, which, being brought under the notice of Pope Urban VIII., obtained for him an appointment in the choir of the Sistine Chapel at Rome.
But the most celebrated composition of Allegri is the Miserere, still annually performed in the Sistine Chapel at Rome.
At the papal order there arose the Ponte Sisto, the hospital of San Spirito, Santa Maria del popolo, Santa Maria della pace, and finally the Sistine Chapel, for the decoration of which the most famous Tuscan and Umbrian artists were summoned to Rome.
But a still more striking period of art is represented by the Vatican, with its antique collections, the Sistine and the Stanze.
In Santa Maria Maggiore the pope erected the noble Sistine Chapel, in which he was laid to rest.
For Holy Week in 1821 by order of Pope Pius VII., has taken a permanent place in the services of the Sistine chapel during Passion Week.
He established and richly endowed the first foundling hospital, built and repaired numerous churches, constructed the Sistine Chapel and the Sistine Bridge, improved church music and instituted the famous Sistine choir, commissioned paintings on the largest scale, pensioned men of learning, and, above all, immortalized himself as the second founder of the Vatican library.
A very pretty curly-headed boy with a look of the Christ in the Sistine Madonna was depicted playing at stick and ball.