[1] During the first half of the 20th century it became the residence and headquarters of Benito Mussolini, dictator of Fascist Italy (1922–1943), who made notable orations from its balcony to huge crowds filling the Piazza Venezia.

The original structure of this great architectural complex consisted of a modest medieval house intended as the residence of the cardinals appointed as the titular holders of the Basilica of Saint Mark.

[3] Between 1466–1469,[4] Pope Paul II added at the south-east corner a large square three storied cloister enclosing a garden, which structure was known as the Viridarium ("Green Area") or Palazzetto ("Little Palace").

[5] This structure was demolished in 1910 and rebuilt on a similar scale and reusing many original materials, 100 metres to the west to fit in with the construction of the massive Victor Emmanuel II Monument on the Capitoline Hill, scheduled for completion in 1911.

"The pope received Charles V with all honours"[7] and the meeting concluded successfully and "resulted in the publication of a papal bull calling all patriarchs, archbishops, bishops, and abbots to assemble at Mantua on 23 May 1537, for a general council".

In order to reach this securely and privately, he built a viaduct (known as the Arch of Saint Mark, or Passetto) from the tower to the top floor of the south-east corner of the Palazzetto, "replicating the palace-passageway-fortress system" which links the Vatican and Castel Sant'Angelo.

During the first half of the 20th century it became the residence and headquarters of Benito Mussolini, dictator of Fascist Italy (1922–1943), who made notable orations from its balcony to huge crowds filling the Piazza Venezia.

On the advice of Achille Starace, Mussolini as a rule left the lights on in his office over night in order to cultivate an image of a workaholic totally dedicated to official business—"a man who never sleeps", as repeated by the Fascist propaganda.