Roman siege engines were, for the most part, adapted from Hellenistic siege technology. Relatively small efforts were made to develop the technology; however, the Romans brought an unrelentingly aggressive style to siege warfare that brought them repeated success. Up to the first century BC, the Romans utilized siege weapons only as required and relied for the most part on ladders, towers and rams to assault a fortified town. Ballistae were also employed, but held no permanent place within a legion's roster, until later in the republic, and were used sparingly.Julius Caesar took great interest in the integration of advanced siege engines, organizing their use for optimal battlefield efficiency.