The first complete history of the Altar of Peace dedicated in ancient Rome to the emperor Augustus Caesar. The monument was restored under the auspices of Benito Mussolini in 1938 to commemorate the bi-millennial birth of Augustus. It is now being refurbished in the Ara Pacis museum in Rome by the American architect Richard Meier. The author disputes the date of this monument, as well as the integrity of the reconstruction, He brings an avalanche of evidence to bear on its reassignment as a commemorative monument assembled not under the reign of Augustus but rather under that of his successor, the emperor Tiberius. The author also offers new interpretation of the iconography of the many relief sculptures that adorn the monument.