After leaving office, the consuls were assigned by the Senate to a province to administer as governor. The provinces to which each consul was assigned were drawn by lot and determined before the end of his consulship. Transferring his consular imperium to proconsular Imperium, the consul would become a proconsul and governor of one (or several) of Rome's many provinces. As a proconsul, his imperium was limited to only a specified province and not the entire Republic. Any exercise of proconsular imperium in any other province was illegal. Also, a proconsul was not allowed to leave his province before his term was complete or before the arrival of his successor. Exceptions were given only on special permission of the Senate. Most terms as governor lasted between one and five years.