Scylletium (near Catanzaro). He spent most of his career trying to bridge the divides of East and West, Greek and Latin cultures, Romans and Goths, and official Christianity and Arian Christianity, which was the form of Christianity of the Ostrogoths and which had earlier been banned. He set up his Vivarium (monastery) in Scylletium. He oversaw the collation of three editions of the Bible in Latin. Seeing the practicality of uniting all the books of the Bible in one volume, he was the first who produced Latin Bibles in single volumes. The most well-known of them was the Codex Grandior which was the ancestor of all modern western Bibles. Cassiodorus was at the heart of the administration of the Ostrogothic kingdom. Theodoric made him quaestor sacri palatii (quaestor of the sacred palace, the senior legal authority) in 507, governor of Lucania and Bruttium, consul in 514 and magister officiorum (master of offices, one of the most senior administrative officials) in 523. He was praetorian prefect (chief minister) under the successors of Theodoric: under Athalaric (Theodoric's grandson, reigned 526–34) in 533 and, between 535 and 537, under Theodahad (Theodoric's nephew, reigned 534–36) and Witiges (Theodoric's grandson-in-law, reigned, 536–40). The major works of Cassiodorus, besides the mentioned bibles, were the Historia Gothorum, a history of the Goths, the Variae and account of his administrative career and the Institutiones divinarum et saecularium litterarum, an introduction to the study of the sacred scriptures and the liberal arts which was very influential in the Middle Ages. Byzantine (Eastern Roman) Emperor Justinian I, retook Italy from the Ostrogoths between 535 and 556. They soon lost much of Italy to the Lombards between 568 and 590, but retained the south for around 500 years until 1059–1071, where they thrived and where the Greek language was the official and vernacular language. In Calabria and towns such as Stilo and Rossano and San Demetrio Corone achieved great religious status. From the 7th Century many monasteries were built in the Amendolea and Stilaro Valleys and Stilo was the destination of hermits and Basilian monks. Many Byzantine churches are still seen in the region. The 10th-century church in Rossano, together with the "twin" church of Sant'Adriano in San Demetrio Corone (foundation 955, rebuilt by the Normans on the, still, visible foundations of the previous Byzantine church), are considered between the best preserved Byzantine churches in Italy. They were both built by