From the very beginning, the Gallery was conceived as a large boardroom, which was to celebrate the victory of the Christian fleet over the Turks at the Battle of Lepanto in 1571. The commander of the Papal fleet, Marcantonio II Colonna, is depicted numerous times throughout the vault of the Great Hall of the Gallery and in the Room of the Battle Column.

The Gallery includes works by Lorenzo Monaco, Domenico Ghirlandaio, Palma the Elder, Salviati, Bronzino, Tintoretto, Pietro da Cortona, Annibale Carracci (painting of The Beaneater), Guercino, Francesco Albani, Muziano and Guido Reni. Ceiling frescoes by Filippo Gherardi, Giovanni Coli, Sebastiano Ricci, and Giuseppe Bartolomeo Chiari celebrate the role of Marcantonio II Colonna in the battle of Lepanto (1571).