What is "successianus"

Successianus was a Roman soldier, general and praetorian prefect in the third century AD of whom very little is known for certain. He is said to have distinguished himself as commander of the garrison of an allied city besieged by barbarian pirates, and then made praetorian prefect by the emperor Valerian on the strength of this. As praetorian prefect appears to have done useful work in restoring Antioch, the capital of the Roman East, after the devastation which had been inflicted by Shapur, the King of the Persians, in his invasion of 252. However, he was overwhelmed by the circumstances with which he had to contend when Shapur invaded on a second occasion in 260 and seems to have shared in the defeat of Valerian at the Battle of Edessa and his subsequent captivity in Persia.