This square was made during the papacy of Paul III Farnese (1534-49) as part of a more complex project aimed to give a new look to the city in view of the allocation of the Duchy of Parma and Piacenza to his son Pier Luigi. On that occasion, was dismantled the old church of San Giovanni de Domo (VIII sec.) and the Bishop's palace was built, putting it beside the Cathedral. The original portico façade was demolished and rebuilt in 1858 by architect Tassini. Divided into three rows of windows, since 1898 it includes a clock and the cote af arms of Pope Pius IX. The square is surrounded by a porch dated back to 1555, and in the center there is the bronze monument dedicated to the Immaculate (1862), which stands on a high monolithic column coming from Palazzo Farnese. The basement was built in memory of the tragic bombing of May 2, 1944 that affected Piazza Duomo causing many victims. The Cathedral of Our Lady of the Assumption, was built as a replacement of an older building dedicated to Saint Justine, built around year 885 and distroyed by an earthquake in 1117. The genesis of the monument, which authorship still remains unknown, started in 1122 when the Bishop Aldo dei Gabrieli laid the foundation, a testimony the prodigious economic and cultural revival that marked the eleventh and twelfth centuries.