St. Michael's Church was built in two stages. The first encompassed the years 1583-1588. Though the architect of the original church is unknown, the church was designed to be one of the largest and finest Jesuit churches in the world. This first phase involved a large barrel-vaulted roof which was second only to the one at St. Peter's in Rome. The vaulting was so massive that locals feared it would collapse.The vaulting never caused a problem but, in 1590, the tower collapsed, destroying the choir, which had just been completed. In response to the disaster, the Duke decided that bad omens dictated a need for an even larger church so he added to his original plans.