This area of the Roman Provincia Nostra was well-populated and accessible by a major highway –the Via Iulia Augusta passed thru on its way from Antibes to Fréjus. Unlike those towns, however, Cannes did not exist as a city, but merely as farms and factories along the coast.
With the collapse of security after the fall of the Empire, the area became largely depopulated, with a nadir in 891 when the Saracens invaded and held the territory for 80 years. After William the Liberator kicked out the Moors in 972, reconstruction began, and Cannes proper first appears in a document from 1030.
It is largely an accident that turned Cannes into what it is today. In 1834, the Lord Chancellor of Great Britain, Henry Brougham, was taking his daughter to Italy to take care of her respiratory ailment; but the Italian border, at Nice back then, was closed off because of the cholera. Backtracking along the road, he spent a few nights at Cannes, and liked it so much, he built a magnificent villa here and launched it as an internationally fashionable resort town.