The explanation of the arrival of Diana is simple. The _dies natalis_ of the temple is the same as that of the famous shrine of the same goddess at Aricia--the Ides of August.[489] Aricia was at this time the centre of a league of cities including Tusculum and Tibur, with both of which, as we have just seen, Rome was closely connected at this time; a league which is generally supposed to have superseded that of Alba, marking some revolution in Latium consequent on the fall of Alba.[490] Diana was a wood-spirit, a tree-spirit, as Dr. Frazer has taught us, with some relation to the moon and to the life of women; of late she has become familiar to every one, not as she was known later, in the disguise of Artemis, but as the deity of that shrine--"pinguis et placabilis ara Dianae"--of which the priest was the Rex Nemorensis: he who "slew the slayer and shall himself be slain."[491] But in those days it was only the fact that she was the chief local deity of Aricia, the leading city of the new league, which brought her suddenly into notice. When the strategic position of Rome gave her in turn the lead in Latium, Diana passed on from Aricia to the Tiber, entered on a new life, and eventually took over the attributes of Artemis, with whom she had much in common. The Diana whom we know in Roman literature is really Artemis; but Diana of the Aventine, when she first arrived there, was the wood-spirit of Aricia, and her temple was an outward sign of Rome's new position in Latium: it was built by the chiefs of the Latin cities in conjunction with Rome, and is described by Varro as "commune Latinorum Dianae templum."[492] It was appropriately placed on the only Roman hill which was then still covered with wood, and was outside the _pomoerium_. There was one other goddess, a Latin one, who was traditionally associated with this period, and especially with king Servius Tullius--Fortuna, or Fors Fortuna; she does not appear in the calendar, had no _flamen_, and must have been introduced from outside. But it was long before Fortuna became of any real importance in Rome, and I shall leave her out of account here. She had two homes of renown in Latium, at Antium and Praeneste, and was in each connected with a kind of oracle, which seems to have been specially resorted to by women before and after childbirth. She was also very probably a deity of other kinds of fertility; and in course of time she took on the characteristics of the Greek Tyche, and became a favourite deity of good luck.[493]