According to late literary sources (not backed by numismatic or inscriptional evidence) a province of Assyria was also proclaimed,[60] apparently covering the territory of Adiabene.[61] Some measures seem to have been considered regarding the fiscal administration of Indian trade – or simply about the payment of customs (portoria) on goods traded on the Euphrates and Tigris.[62][57] It is possible that it was this "streamlining" of the administration of the newly conquered lands according to the standard pattern of Roman provincial administration in tax collecting, requisitions and the handling of local potentates' prerogatives, that triggered later resistance against Trajan.[63]