In the reign of Claudius an artificial port was formed on the right arm of the Tiber, which was deeper, the course of the river having been regulated. Trajan extended the port, and this _Portus Romanus_ now became the real sea-port of Rome, a depôt for the immense supplies required for the city. At present, too, the little maritime commerce of the Romans is carried on along the right bank of the Tiber. I will not mention all the places of ancient Latium which happen to be once noticed by ancient writers, many of them are mere names of destroyed places; much more might indeed be made out than has yet been done, but the advantages would not be very considerable. We must conceive Latium in the earlier times to have been divided into three parts: 1. _Alba and its perioeci_, or thirty neighbouring and dependent places, said to have been colonies, and called _Albenses_; 2. the _Latin demi_, about Alba and its territory, the number of which we may assume, without fear of being mistaken, to have likewise amounted to thirty. They formed the Latin state, and stood in the same relation to Alba in which Latium afterwards stood to Rome; 3. the _Tyrrhenian towns on the coast_, which were properly foreign to the body of the Latin state, but may possibly have been in alliance with it. I have succeeded in throwing more light upon this relation between Alba and the Latin towns than I myself could formerly have expected; I have found all the names of the thirty Albensian towns, but the list of the others is not complete.