How did Ancient Rome, with its gigantic empire, organize its fiscal system? There were many local traditions to take into account while building the Roman tax administration. So many specific situations were acknowledged that one might even wonder whether there was such a thing as "a Roman taxation system" at all. By studying preroman fiscal systems and their evolution in the immediate aftermath of Roman integration, this book aims to demonstrate the empirical running of Roman administration and its ability to adapt to different contexts in order to build an empire.