A glance at the map of Italy will show us at once how apt is Livy's remark that Rome was placed in the centre of the peninsula.[6] That peninsula looks as if it were cleft in twain by the Tiber, or in other words, the Tiber drains the greater part of central Italy, and carries the water down a well-marked valley to a central point on the western coast, with a volume greater than that of any other river south of the Po.

A city therefore that commands the Tiber valley, and especially the lower part of it, is in a position of strategic advantage with regard to the whole peninsula.

Now Rome, as Strabo remarked, was the only city actually situated on the bank of the river; and Rome was not only on the river, but from the earliest times astride of it.

She held the land on both banks from her own site to the Tiber mouth at Ostia, as we know from the fact that one of her most ancient priesthoods[7] had its sacred grove five miles down the river on the northern bank.
Thus she had easy access to the sea by the river or by land, and an open way inland up the one great natural entrance from the sea into central Italy.[8] Her position on the Tiber is much like that of Hispalis (Seville) on the Baetis, or of Arles on the Rhone, cities opening the way of commerce or conquest up the basins of two great rivers.

In spite of some disadvantages, to be noticed directly, there was no such favourable position in Italy for a virile people apt to fight and to conquer.