By the end of the 7th century B.C., the villages of Latium had probably become cities that united in a federation of 30 such towns for religious festivals (feriae Latinae) and legal functions. Its center was at the Mount of Alba [see Alban Mountains]. The Latin League could exact the death penalty for violation of the law of the federation. It does not seem the league prevented the federated cities from waging war. On the other hand, it appears the Latin League maintained the right to wage its own wars.
The Latin League moved to Aricia from Alba when Tullus Hostilius, who destroyed Alba Longa, was king of Rome. The famous legend of Horatius standing at the bridge is from the destruction of Alba Longa.
Rome made an alliance (a foedus aequum 'equal terms alliance'), known as the Cassian Treaty, with the Latin League in 493 B.C. By the Cassian Treaty, the Latin League and Rome were equal (aequum) partners. By the middle of the next century, Rome was in charge. The Latin League ended in 338 B.C.