Alalia led to a new distribution of power in the western Mediterranean. Though the battle had no clear winner, Carthage managed to expand its sphere of influence at the expense of the Greeks, and Etruria saw itself relegated to the northern Tyrrhenian Sea with full ownership of Corsica. From the first half of the 5th century BC, the new political situation meant the beginning of the Etruscan decline after losing their southern provinces. In 480 BC, Etruria's ally Carthage was defeated by a coalition of Magna Graecia cities led by Syracuse, Sicily. A few years later, in 474 BC, Syracuse's tyrant Hiero defeated the Etruscans at the Battle of Cumae. Etruria's influence over the cities of Latium and Campania weakened, and the area was taken over by Romans and Samnites. In the 4th century BC, Etruria saw a Gallic invasion end its influence over the Po Valley and the Adriatic coast. Meanwhile, Rome had started annexing Etruscan cities. This led to the loss of the northern Etruscan provinces. During the Roman–Etruscan Wars, Etruria was conquered by Rome in the 3rd century BC. Etruscan League According to legend, there was a period between 600 BC and 500 BC in which an alliance was formed among twelve Etruscan settlements, known today as the Etruscan League, Etruscan Federation, or Dodecapolis (in Greek Δωδεκάπολις). According to a legend the Etruscan League of twelve cities was founded by Tarchon and his brother Tyrrhenus. Tarchon lent his name to the city of Tarchna, or Tarquinnii, as it was known by the Romans. Tyrrhenus gave his name to the Tyrrhenians, the alternative name for the Etruscans. Although there is no consensus on which cities were in the league, the following list may be close to the mark: Arretium, Caisra, Clevsin, Curtun, Perusna, Pupluna, Veii, Tarchna, Vetluna, Volterra, Velzna, and Velch. Some modern authors include Rusellae. The league was mostly an economic and religious league, or a loose confederation, similar to the Greek states. During the later imperial times, when Etruria was just one of many regions controlled by Rome, the number of cities in the league increased by three. This is noted on many later grave stones from the 2nd century BC onwards. According to Livy, the twelve city-states met once a year at the Fanum Voltumnae at Volsinii, where a leader was chosen to represent the league. There were two other Etruscan leagues ("Lega dei popoli"):