As he was only ten years old, the regency was assumed by his mother Amalasuntha. His mother attempted to provide for him an education in the Roman tradition, but the Gothic nobles pressured her to allow them to raise him as they saw fit. As a result, he drank heavily and indulged in vicious excesses, which ruined his constitution.
The clear import of Athalaric's words is that the literary talents of Cassiodorus were so remarkable in the Ostrogothic court that whenever he was in Ravenna some significant public documents were entrusted to him for drafting, no matter who technically exercised of quaestor.
While Theoderic's grandson Athalaric held the throne, it was the boy's mother Amalasuintha who held the power; she knew the benefits of Roman education and was determined to pass them on to her son.
Athalaric died shortly afterwards in early 534, and the remainder of Cassiodorus' public career fell under storm clouds of Byzantine reconquest and dynastic intrigue among the Ostrogoths.