Today’s entry from A Concise Dictionary of Greek and Roman Antiquities is praefectus Aegypti. It is actually a subsection of the larger entry “praefectus.”
PRAEFECTUS AEGYPTI. Egypt was not included by Augustus either in the senatorial or in the imperial provinces, but was reserved for his more immediate control. It was governed by a procurator of equestrian rank, praefectus Aegypti (Tac. Hist. ii. 74, &c.), or in Greek hghmwn. His staff consisted of freedmen of the emperor. Everything but the fixing of the revenues and the right of appointment to certain posts was in his hands: the administration of finance, the judicial authority, and the supreme military command. The Praefectus Aegypti held rank second in the scale of the non-senatorial dignities, coming after the praefectus praetorio, but before the praefectus annonae.
The OCD does not have an entry “praefectus Aegypti,” and it is only mentioned in passing in the general article “praefectus.” In the entry “Egypt,” we read: “After two centuries of diplomatic contacts, Egypt was annexed as a province of the Roman people in 30 BC by Octavian (Augustus) after his defeat of Mark Antony and Cleopatra VII. Although the Romans adapted many individual elements of the centralized bureaucracy of the Ptolemaic kingdom, and although the emperor could be represented as a pharaoh, the institutions of the Ptolemaic monarchy were dismantled, and the administrative and social structure of Egypt underwent fundamental changes. The governor (prefect) and other major officials were Roman equites appointed, like the administrators of other ‘imperial’ provinces, by the emperor for a few years.” There were many more changes, enumerated in the rest of the paragraph.