The Palazzo Chigi is a palace or noble residence in Rome and the official residence of the Prime Minister of the Italian Republic. Since December 12, 2016, the occupant of Palazzo Chigi is Paolo Gentiloni.
The Palazzo, overlooking the Piazza Colonna and the Via del Corso, was begun in 1562 by Giacomo della Porta and completed by Carlo Maderno in 1580 for the Aldobrandini family. In 1659 it was purchased by the Chigi family. It was then remodelled by Felice della Greca and Giovan Battista Contini. It has five floors, a broad stairway that leads to the living rooms, and a courtyard decorated with a fountain, designed by Giacomo della Porta. The fountain has been copied in many sites in Rome and other Italian cities.
In 1878 it became the residence of the Austro-Hungarian Ambassador to Italy. In 1916 it was bought by the Italian state and became the seat of the Minister for Colonial Affairs. Later it was the official residence of the Italian Minister of Foreign Affairs. In 1961 it became the official meeting place of Council of Ministers whose President is the head of the Italian government.
The Library Hall was commissioned by Agostino Chigi at the end of the 17th century in order to house the enormous library of cardinal Flavio Chigi. The project was realized by Giovan Battista Contini, a famous architect of the period.
The Chigi library or Chigiana contained thousands of valuable manuscripts, to a large part based on the personal library of Pope Alexander VII, a member of the Chigi family. Since the time of Pope Benedict XV, the Vatican attempted to acquire this library, but lacked the necessary funds. Eventually, Pietro Tacchi Venturi was tasked by Pope Pius XI to negotiate the purchase with the newly formed fascist government of Benito Mussolini. Venturi managed to convince Mussolini to donate the library to the Vatican free of charge.