How lucrative was Egypt to the Byzantines?

[Drewbdu]

I recall reading that Egypt provided 50% of the income of the Ottoman Empire at some points, and I am wondering whether this was the case with the Byzantines. I know that Egyptian grain production and storage was integral for the population of Byzantium (shown when famine struck after Cairo was conquered by the Arabs), but did the province provide very high monetary benefits?

 

[Calad]

Since roman times very high. The issue was that Greeks were ortodox while Egyptians were Coptic. This led Byzantines to neglect defense of Egypt and Arabs literally rided in.

 

[trybald]

he issue was that Greeks were ortodox while Egyptians were Coptic. This led Byzantines to neglect defense of Egypt and Arabs literally rided in.

Coptic church won over Egypt only in early 7th century, under Persian occupation. Earlier it was (together with Syria and Anatolia) a battleground between rival patriarchs with local parishes caught in between. "Coptic Egypt", "Miaphysyte Syria" and "Orthodox Anatolia" are a state of affairs that in reality was stabilized only after the Arab conquests.

Also, Egypt was the one provice the Byzantines actually fought tooth and nail to keep. They conceded the loss of Syria, but really tried to save Egypt.

I recall reading that Egypt provided 50% of the income of the Ottoman Empire at some points, and I am wondering whether this was the case with the Byzantines.

We don't know. Probably significant, but we don't have the Empire's accounting books.

I know that Egyptian grain production and storage was integral for the population of Byzantium

Debatable to be honest. The Egypt was finally lost in 646, with graint supply already distrupted in 639. Constantinople was depopulated by Constantine IV before the First Siege (674). So, in between we have more than thirty years in which the Empire is able to feed its population, including the capital itself, without Egyptian grain.

(shown when famine struck after Cairo was conquered by the Arabs)

Cairo was founded in 10th century.

Also, the worst famine in 7th century likely happened in 608 and it was directly connected to the rebellion of Heraclius in Africa.

 

[Semper Victor]

It's impossible to know with certainty. We can assume that it was fairly high, but other than that, we lack reliable data about it. Up until the 610s though, Egypt was a very umportant pillar of the imperial tax system, as it had neither been raided nor attacked by enemy forces since the 270s, was densely populated and enjoyed a stable environment for agriculture. And then there was the fact that Egypt provided the imperial fiscus with the annona frumentaria, the grain tribute which the imperial authorities used for the food dole that kept the population of Constantinople at artificially high levels until the VII century. After the Sassanians seized Egypt in 616 AD, the system was discontinued by Heraclius and was never again restored, which caused a steep decline of the population of Constantinople to levels that could be supplied with grain traded from the Aegean and Black sea coasts. A similar thing happened to the city of Rome after the Vandals seized Carthage in 439 AD.

 

[joak]

This led Byzantines to neglect defense of Egypt and Arabs literally rided in.

The more immediate cause of the poor defense of Egypt was the long Persian war. When the Arabs really started up, Egypt had been under Byzantine control for like 2 years of the last 3 decades or something.