The immense hall, 54 metres long and 23 metres wide, is lined with Vasari's battle frescoes and statues, among them Vincenzo de' Rossi's Labours of Hercules and Michelangelo's Genius of Victory, beneath a gilded ceiling of painted panels. Built in 1494 for the Great Council of five hundred citizens of the Republic, it was transformed by Giorgio Vasari for Cosimo I between 1555 and 1572.