Gainas chose Caesarius as successor to Aurelianus to the office of Praetorian prefect of the East, but, after a short time, he left Constantinople and was defeated by the magister militum per Orientem Fravitta.
Gainas memilih Caesarius sebagai pengganti Aurelianus ke kantor prefek Pretorian Timur, tetapi setelah beberapa waktu, ia meninggalkan Konstantinopel dan dikalahkan oleh magister militum per Orientem Fravitta.