The rise of the Sassanians is better documented than subsequent history, but even so there are conflicting versions of the origin of Ardashir. The first capital of Ardashir in Fars most likely was at Firuzabad, then known as Gor, although later in the reign of Ardashir it received the name Ardashir-khwarreh 'the glory of A', probably in honour of his victories over the Parthians. The Sassanians respected and feared the mighty Roman Empire and continued to designate the later Byzantine state by the same name, although they knew that different peoples lived in the enemy state and served in its armies. The Romans too learned to respect the Sassanians more than they had the weaker Parthians. Perhaps the most significant changes in outlook, culture and society in the third and fourth centuries, both in the Roman and the Sassanian worlds, were the changes in religion which marked the end of the old 'pagan' religions and the flowering of 'universal' religions.