The necessity of protecting those suburbs from the incessant inroads of the barbarians engaged the younger Theodosius to surround his capital with an adequate and permanent enclosure of walls.

From the eastern promontory to the golden gate, the extreme length of Constantinople was about three Roman miles; the circumference measured between ten and eleven; and the surface might be computed as equal to about two thousand English acres.

It is impossible to justify the vain and credulous exaggerations of modern travellers, who have sometimes stretched the limits of Constantinople over the adjacent villages of the European, and even of the Asiatic coast.

But the suburbs of Pera and Galata, though situate beyond the harbor, may deserve to be considered as a part of the city; and this addition may perhaps authorize the measure of a Byzantine historian, who assigns sixteen Greek (about fourteen Roman) miles for the circumference of his native city.

Such an extent may not seem unworthy of an Imperial residence.