Once completed, San Giovanni became the national church of Florence in Rome. Pope Leo X initiated an architectural competition in 1508 for a new church to be built in place of the old Saint Pantaleo. THe winning architect went by the name of Sansovino but there were complications and construction slowly ground to a halt. Many different people tried to finish the church over two centuries, and it was finally completed in 1734.
There's something to be said for the efficiency of a dictatorship, although the death toll accompanying one is a little unsettling.