 However , Constantine certainly did not patronize Christianity alone . After gaining victory in the Battle of the Milvian Bridge ( 312 ) , a triumphal arch — the Arch of Constantine — was built ( 315 ) to celebrate his triumph . The arch is decorated with images of the goddess Victoria . At the time of its dedication , sacrifices to gods like Apollo , Diana , and Hercules were made . Absent from the Arch are any depictions of Christian symbolism . However , as the Arch was commissioned by the Senate , the absence of Christian symbols may reflect the role of the Curia at the time as a pagan redoubt . 
