Hall 9 along with the south end of the great hall and hall X was built at the time of the 1543 expansion and renovation of the mansion. Painted external wall then became internal wall of the extended building and was covered over with episodes from the life of Alessandro Magno painted by Cola dell'Amatrice and assistants in1545. Among these episodes we can distinguish the Battle of Isso, the Defeat of Dario, Dario Dying, Alessandro and king Poro. Its not surprising that this small room which probably served Alessandro Vitelli as a study was painted with subjects from the life of his hero; he also was a military man of fame in his period. Cola, in his mural painting, represented Bucefalo, Alessandro's horse, as a unicorn. The unicorn was the symbol of the Farnese family and Alessandro and Ottaviano Farnese were appointed in 1546 by Pope Paul III to lead in army against the lutherans Cola's participation in the decoration of the mansion was a logical consequence of the fact that his hometown, Amatrice, had been incorporated within the domains of the Vitelli family.