 Such spans were three times as wide as the widest prop-and-lintel roofs and only surpassed by the largest Roman domes.The largest truss roof by span of ancient Rome covered the Aula Regia (throne room) built for emperor Domitian (81–96 AD) on the Palatine Hill, Rome.The timber truss roof had a width of 31.67 m, slightly surpassing the postulated limit of 30 m for Roman roof constructions.