Next in importance to the musical competitions were the chariot and horse races, which rivalled in popularity even those at Olympia. At first they were confined, as at Olympia, to the four-horse chariot and the horse race. The pair-horse chariot-race (συνωρίς) and the chariot-race for colts were introduced at Delphi in 398 B.C. and 378 B.C., only a few years after their introduction at Olympia. The remaining two events, the synoris for colts and the riding race for colts, which were introduced at Delphi in 338 B.C. and 314 B.C., did not figure at Olympia till the next century. The popularity of horse-racing at Delphi was due to the wide-spread influence of the Delphic oracle among the Greek colonies, and particularly to the intimate connexion between Delphi and the great horse-breeding lands of Northern Greece, which belonged to the Thessalian Amphictyony; at a later time also to the influence of Macedon. Delphi was no less accessible than Olympia to the Greeks on either side of the Corinthian Gulf, and to the colonies of the West, and of Africa. The earliest victor in the chariot-race was Cleisthenes of Sicyon, and in the fifth century we find among the victors Megacles, the Alcmaeonid of Athens; Hieron of Syracuse, twice victor in the horse-race, once in the chariot-race; Xenocrates of Agrigentum, for whom Pindar wrote his earliest hymn of victory; and Arcesilas of Cyrene. The “Charioteer” is supposed by some archaeologists to be part of the monument commemorating the victory of Arcesilas.