The first palace on this site was built in 1244, but the palace in its modern forms was begun in epoch of Julius II and Leo X in the beginning of the 16th century, with participation ofMichelangelo in course of project creation. The definite remodeling is work of G.Della Porta(1575). In particular, he executed the facade and a courtyard. After some time Sixtus V had the northern facade to be done. Urban VIII ordered construction of a Chapel and Alexander VII founded here a library (Biblioteca Alessandrina). On the facade is inscribed "Initium/ Sapientiae/ Timor Domini".