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.
St. Mary's Basilica, Kraków
The church was completely rebuilt during the reign of Casimir III the Great between 1355 and 1365 with substantial contributions from wealthy restaurateur Mikołaj Wierzynek. The presbytery was elongated and tall windows added. The main body of the church was completed in 1395–97 with the new vault constructed by master Nicholas Wernher from Prague. However, the vault over the presbytery collapsed in 1442 due to a possible earthquake, which has never happened before nor since in Kraków.