Santa Maria del Popolo
The architect or architects of this innovative project remain unknown due to a lack of contemporary sources. Giorgio Vasari in his "Lives" attributed all the important papal projects in Rome during Sixtus IV to a Florentine, Baccio Pontelli including the basilica and monastery of Santa Maria del Popolo. Modern researchers deemed this claim highly dubious and proposed other names among them Andrea Bregno, a Lombard sculptor and architect whose workshop certainly received important commissions in the basilica. The fundamental differences between the façade and the interior suggest that maybe more than one architect was working on the building.
Santa Maria del Popolo
In the middle of the 13th century the church was given to the Order of Saint Augustine which has maintained it ever since. The Augustinians were a new mendicant order established under the guidance of Cardinal Riccardo Annibaldi, probably the most influential member of the Roman Curia at the time. Annibaldi was appointed corrector and provisor of the Tuscan hermits by Pope Innocent IV in December 1243. The cardinal convened a meeting to Santa Maria del Popolo for the delegates of the hermitic communities where they declared their union and the foundation of the new order that the Pope confirmed with the bull "Pia desideria" on 31 March 1244.