The origins of Ragusa can be traced back to the 2nd millennium BC, when in its area there were several settlements of the ancient Sicels. The current Ragusa Ibla lies probably on one of them, identified as Hybla Heraea.
The ancient city, located on a 300 m high hill, entered in contact with the nearby Greek colonies, and developed thanks to the nearby port of Camerina. After a short Carthaginian rule, it was administrated by the Romans and the Byzantines: the latter fortified the city and built a large castle. Ragusa was occupied by the Arabs in 848 AD, remaining under their rule until the 11th century, when the Normans conquered it. Selected as County seat, its first Count was Geoffrey, son of Count Roger I of Sicily.
Ragusa thereafter followed the events of the Kingdom of Sicily, created in the first half of the twelfth century. A Chiaramonte family fief, it remained the county capital after the unification with that of Modica in 1296, a status it lost in the 15th century after a popular revolt.
In 1693 the city was devastated by a huge earthquake, which killed some 5,000 inhabitants. Following this catastrophe the city was largely rebuilt, many baroque buildings date from this period. Most of the population moved to a new settlement in the former district of Patro, calling the new municipality "Ragusa Superiore" (Upper Ragusa) and the ancient city "Ragusa Inferiore" (Lower Ragusa). The two cities remained separated until 1926, when they were fused together to become the provincial capital in 1927 at the expense of Modica, the former capital and the most populous and important city in the region since 1296.
In 1838 an asphalt deposit was discovered, which is still being worked