4 surviving letters between Cassiodorus and John, spanning c. 522–522.
King Theodoric to John, Vir Spectabilis [Most Respectable], Governor [Consularis] of Campania.
King Theodoric to John, Archiater [Chief Physician].
King Theodoric to John, Vir Clarissimus [Most Distinguished], Treasurer.
Senator [Cassiodorus], Praetorian Prefect, to John, Chancellor.