This measure was taken by Roger l., after the conquest of Naples, (A.D. 1139,) which he made the capital of his new kingdom, (Giannone, Istoria Civile, tom. ii. p. 169.) That city, the third in Christian Europe, is now at least twelve miles in circumference, (Jul. Caesar. Capaccii Hist. Neapol. l. i. p. 47,) and contains more inhabitants (350,000) in a given space, than any other spot in the known world.