Now in control of most of Sicily, Dionysius turned to southern Italy. There he faced the Italiot League, a confederacy of important Greek city-states in the toe and instep of Italy, including Rhegium and Croton. In 390 BC he began a war with Rhegium; Dionysius had one ally in the area: Locri, which he made his headquarters for the war. His fleet of fifty ships intercepted a Greek fleet of sixty ships from Croton which was sailing to the aid of the Rhegians, and a battle began. A storm arose, in which Dionysius lost seven ships and 1500 men. He fled to Messene on the coast of Sicily.[1]
An army of Lucanians, the non-Greek natives of the toe of Italy, invaded and defeated the Greeks of Thurii. Dionysius’ fleet, commanded by his brother Leptines, rescued and ransomed refugees from the Lucanian attack. Grateful for the rescue, the Thurians who had been supporting Rhegium, made peace with Leptines. Dionysius was furious that his brother had let his enemies off so lightly and relieved him of his command.[2]
The following year, Dionysius sent another army and navy against Rhegium and began a siege of their ally Caulonia. A relief force sent from Croton was defeated by Dionysius and surrendered to him. He now besieged Rhegium, which was isolated and deprived of allies. The city surrendered to him for a huge indemnity of three hundred talents and surrendered its fleet. The people of Caulonia also surrendered, after which the city was depopulated and destroyed, and its citizens resettled in Syracuse.[3]
The following year, Dionysius provoked an incident in Rhegium, which led to another siege. He built huge siege machinery to attack the city walls, to no avai. He himself was wounded by a javelin in battle and almost died. He eventually starved the city into submission over eleven months, then carried the survivors to Syracuse, where all those who could not pay a ransom were enslaved.[4]
Dionysius now controlled the western part of Magna Graecia as well as most of Sicily. He was the most powerful man in the Greek world. His ruthless depredations had brought him to the height of worldly fame and influence.
He now sent out colonies along the Adriatic Sea, including Hadria at the mouth of the Po River, the antecedent of Venice. He made alliances with Illyrians in the Balkans, and helped Alcetas become king of the Molossians, who lived in the area of modern Albania. A few years after his other conquests he captured the city of Croton, so that he ruled all the southwestern coast Italy. He levied high taxes to support his wars and used some of the money to build monuments in Syracuse.
[1] Diodorus Siculus 14.100.
[2] Diodorus Siculus 14.101-102.
[3] Diodorus Siculus 14.106.
[4] Diodorus Siculus 14.108, 111.