Felice Peretti
Became Pope in 1585 and died in 1590. A highly effective reforming Pope.
Enforced the Council of Trent’s decrees on clerical discipline and reformed the central administration of the Roman Catholic Church. Transformed the role of Cardinals within the Church and limited their number to seventy. More strictly enforced a minimum age of appointment of 30 for Cardinals. Illegitimate sons were excluded from consideration, as were those who had fathered illegitimate sons.
Sixtus V formulated rules for the amount of time a Bishop/Archbishop/Cardinal was to spend in their own diocese.
Set up fifteen congregations of Cardinals to rule over various tasks. These varied from the physical maintenance of Rome, i.e. Roads, bridges etc., to Doctrinal definition.