So called from the principal fresco that fills the north wall, this hall was originally the bedchamber of Agostino Chigi.

The banker commissioned its decoration from Giovanni Antonio Bazzi, known as Sodoma, a painter who was born in Vercelli but had long been working in Siena and Rome. In 1519, Following an “initial idea” from Raphael, he designed a fresco cycle on the walls of the bedchamber, depicting the wedding of Alexander the Great and his bride Roxana, based on Lucian’s description of a famous lost painting of antiquity.

The centre piece of the narrative reveals the scene of the imminent consummation of the marriage: the Macedonian warrior is shown hurrying towards his bride, who is surrounded by amorinos and is sitting waiting for him naked on the edge of the splendid four-poster bed. The other scenes represent Alexander’s magnanimity towards the mother and daughters of the defeated Darius; the taming of the horse Bucephalus (which is not in Sodoma’s style; the coarse ill-constructed and vulgar figures are late sixteenth century) and the culminating moment of battle.

The ceiling is in the style of the original sixteenth-century caisson ceiling, decorated with grotesque and mythological subjects.