Now let it be recollected that this continual and astonishing decline of agriculture, and disappearance of the rural cultivators in the latter stages of the Roman empire, took place in an empire which contained, as Gibbon tells us, 120,000,000 of inhabitants, and 1600 great cities, was 3000 miles long and 2000 miles broad, contained 1,600,000 square miles, chiefly fertile and well cultivated land, which embraced the fairest and most fertile portions of the earth, and which had been governed for eighty yers under the successive sway of Nerva, Adrian, Trajan, and the two Antonines, with consummate wisdon and the most paternal spirit.[14] The scourge of foreign war, the devastation of foreign armies, were alike unknown; profound tranquillity pervaded every part of the empire; and a vast inland lake, spreading its ample waters through the heart of the dominion, afforded to all its provinces the most perfect facility of intercourse with the metropolis and the central parts of the empire. Yet this period--the period which Mr Hume has told us the philosophers would select as the happiest the human race had ever known--was precisely that during which agriculture so rapidly declined in the Italian and Grecian fields, during which the sturdy race of free cultivators disappeared, and the plains of Italy were entirely absorbed by pasturage, and maintained only vast herds of cattle tended by slaves. [14] "Quingena viginti octo millia quadringinta duo jugera, quae Campania provincia, juxta inspectorum relationem, in desertis et squalidis locis habero dignoscitur, iisdem provincialibus concessum."--_Cod. Theod_. lxi. i. 2382.