The Latin alphabet originated in the 7th century BC being adapted from the Etruscan alphabet.
There was an earlier opinion, supported even by some scholars, that the letters of the Latin alphabet derived directly from the Greek ones. This theory was based on the obvious similarity between the Latin alphabet and the Chalcidian variety of the Western group of Greek scripts used at Cumae in Campania, Southern Italy.
This theory turned out to be inconsistent:
1. Latin letter names are clearly of Etruscan and not of Greek origin
(a, be, ce, de etc. and not alpha, betha, gamma, delta etc.)
2. The [F] sound, in most ancient documents, is represented by combination FH, which was peculiar to the Etruscan writing system.
There is a Roman legend, which credits introduction of alphabet into Latinium to Evander, son of the Cimmerian Sibyl. This was supposed to have happened 60 years before the Trojan war. However, there is no historically sound basis to this tale.
The Etruscans themselves derived their alphabet from the Greek colonists in Italy, more specifically from the Cumae alphabet. The Ancient Greek alphabet was in turn based upon the Phoenician alphabet.
This makes the early Latin alphabet one among several Old Italic alphabets emerging at the time.
The Romans ultimately adopted 21 of the original 26 Etruscan letters.
A B C* D E F Z H I** K L M N O P Q R S T V*** X