Flavius Rufinus (; – 27 November 395) was a 4th-century East Roman statesman of Aquitanian extraction who served as Praetorian prefect of the East for the emperor Theodosius I, as well as for his son Arcadius, under whom Rufinus exercised significant influence in the state affairs. He was the subject of the verse invective In Rufinum by the western court poet Claudian. Life Tall and always in movement, he is described as acute, ambitious, greedy and without principles, but a rigorous Christian. His difficulty with the Greek language is recorded by the sources, as well as his Aquitanian origin. In 388 he was appointed magister officiorum. In 392 he served as Roman consul and in that same year he was appointed as Praetorian prefect of the East. Upon his appointment, he retained the responsibilities of the magister officiorum. In order to become prefect, Rufinus is said to have persuaded the emperor that Eutolmius Tatianus, the current occupant of the position, and his son Proclus, the prefect of Constantinople, committed corruption. Proclus was executed while his father was banished. Emperor Theodosius trusted Rufinus, and he used this influence to fight his opponents at the court. He came into conflict with Promotus and Timasius, respectively Theodosius' magister equitum and magister peditum. During a meeting of the council, Rufinus insulted Promotus, who slapped him; Rufinus went to Theodosius to report the affront, and Theodosius replied that if nothing changed he would have Rufinus appointed co-emperor. Taking advantage of the imperial support, Rufinus suggested Theodosius send Promotus to Thrace, where he would be entrusted with the training of the troops. Some barbarians followed Promotus in his journey, but, having an agreement with Rufinus, they suddenly attacked and killed Promotus (September 392). During the period immediately after Theodosius' death, in January 395, Rufinus was virtually the ruler of the Eastern Roman Empire, since he exercised great influence over the young Emperor Arcadius. An account by the Roman poet Claudian stated that he attempted to further join himself to Arcadius by marrying his daughter to the young emperor. This plan was stymied by another of the imperial ministers, Eutropius. This official, who held the position of chamberlain, arranged instead a marriage with Aelia Eudoxia, who was a child of one of Rufinus' opponents. Rufinus hated the western magister militum Stilicho, and Rufinus's influence over Arcadius prevented Stilicho from crushing Alaric when he had the chance. Stilicho