Flavius Magnus Aurelius Cassiodorus Senator (c. 485 - c. 585), commonly known as Cassiodorus, was a Roman statesman and great writer, serving in the administration of Theodoric the Great, king of the Ostrogoths. "Senator" was his surname, not his rank. Wikipedia
The definitive Wikipedia entry for Cassiodorus. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Cassiodorus