In their widest territorial scope, Anatolian designations were employed during the reign of Roman Emperor Constantine I (306–337), who created the Praetorian prefecture of the East, known in Greek as the Eastern Prefecture, encompassing all eastern regions of the Late Roman Empire and spanning from Thrace to Egypt.
In their broadest territorial extent, Anatolian designations were utilized during the rule of Roman Emperor Constantine I (306–337), who established the Praetorian prefecture of the East, known in Greek as the Eastern Prefecture, enveloping all eastern territories of the Late Roman Empire and extending from Thrace to Egypt.