The original structure of the fortress of Castel St.Angel in Rome, together with the Elio bridge in front of it, nowadays known as Ponte Sant'Angelo, are built by the Architect Demetriano between 117 and 138 after Christ, as a mausoleum for the family of the Imperator Adriano.
The Sistine Chapel, wanted by Pope Sisto IV della Rovere, from which it takes its name, was built by Giovannino de'Dolci between 1475 and 1481 after Christ.
In 1498 after Christ, Michelangelo, only 22 years old, writes a contract, guaranteed by Jacopo Galli, with the French Cardinal of San Dionigi, for the realization, within a year, of a "Pietà" (pity) in marble destined to be placed in the Basilica of San Pietro.