The palace was built in 1455, when the Venetian Cardinal Pietro Barbo was named titular of the Basilica of Saint Mark. Nine years later he became Pope Paul II (1464-71) and so he enlarged the palace structure while his cardinal-nephew, Marco Barbo, was assigned to the basilica.
During this period three monumental halls were created: the Regia Room, the Concistory Room (later named the Battles Room), the Mappamondo Room, and especially the Viridarium, a covered garden adjacent to the great tower of the palace (Torre della Biscia). At the end of XVth century further to the existing Papal rooms, named Barbo apartment, other rooms were added and called Cybo apartment, named after the first cardinal who lived there, Lorenzo Cybo nephew of Pope Innocenzo VIII (1484-1492). The palace of Saint Mark was used as a papal summer residence until 1564, when Pius IV Medici (1559-1565) gave it to the Republic of Venice, which established here its Roman embassy. Since then it has been called Palazzo ‘of’ Venezia which is its current name. The building was property of Venice up until the Republic existed. After the Treaty of Campoformio, in 1797, Palazzo Venezia became the Austrian diplomatic seat. From 1910 to 1913 the ancient garden of Paul II, called Palazzetto, was demolished to create Piazza Venezia and rebuilt on the other side of the palace, near via delle Botteghe Oscure. In 1916 the Italian Reign recovered the building and the art historian Federico Hermanin was nominated to create a National Museum, which opened in 1921, and to direct the restoration in order to recreate a Renaissance image, lost over the centuries. From 1929 to 1943 the Palace became the Fascist head-quarters and after the Second World War the museum opened again to the public. Since 1981 the Barbo apartment and the monumental halls are used for temporary exhibitions, while the Cybo apartment and the Palazzetto house the museum collections. Paintings, wooden sculptures, furniture, porcelains, ceramics, bronzes, marbles, terracottas and armoury make the Museum of Palazzo Venezia the most eclectic in Rome.