Those parts of the religion of Greece and Rome which were common to both were probably Pelasgian.
Let us take first the names which correspond, and then those which are different.
(I.) Names of deities that correspond in the Greek and Latin tongues:
1. Ζεύς Deus. 2. Ζεὺς-πάτηρ Jupiter. 3. Ἀπόλλων Apollo. 4. Ἱστιή Vesta. 5. Λήτω Latona. 6. Περσεφόνη Proserpina. 7. Ἄρης Mars or Mavors.
(II.) Names of deities which do not in any manner correspond in the Greek and Latin tongues:
1. Ἥρη Juno. 2. Ποσειδὼν Neptune. 3. Ἀιδώνευς Pluto. 4. Ἀθήνη Minerva. 5. Ἥφαιστος Vulcan. 6. Ἑρμῆς Mercury. 7. Ἀφροδίτη Venus. 8. Ἄρτεμις Diana. 9. Δημήτηρ Ceres. 10. Διόνυσος Bacchus.
Two remarks may be made on the deities of the first list.
First, that it comprehends generally the gods whom we shall find to bear marks of being the most ancient among the Greek deities; with the marked exception, however, of Minerva[516].
Secondly, that in it we find no deity who takes part on the Greek, that is, the Pelasgian side, in the war of Troy. The only two names which do not appear on the Trojan side, are Vesta, who with Homer is not personified at all: and Proserpine, who from the seat of her dark dominion could not share in the wars waged upon earth.
On the other hand, when we turn to the second list of exclusively Greek names, we find that it contains all the deities who took part against Troy: and only two very secondary names of deities friendly to it.
Mars and Venus, both engaged on the Trojan side, and one standing in the first list, are the deities after whom, according to Ovid[517], the two first months of the Roman year were named in the first age of the city.
It would not, however, be safe to depend implicitly upon the apparent reappearance of certain names in the Latin language, without a fuller knowledge of the laws of discrimination between the early mythology of the Romans, and the form which their religious system assumed at the period when they came into free communication with Greece and its colonies, from which, as they certainly borrowed some names of deities, such as Pallas and Phœbus, so they may have assumed others too. We have no proof, for example, that Apollo was prominent, or even that he was known, in the earliest Roman worship. Cicero[518] says, _Jam Apollinis nomen est Græcum_. Still, a temple was raised to him in Rome[519] as early as 430 B. C.; and the Trojan sympathies of most of the deities in the first list tend in some degree to show both that they were well known in the Pelasgian religion, and that many of the older portions of the mythology were common to the Trojans, the early Romans, and the Pelasgians of Greece.