The cathedral has been destroyed and rebuilt several times because of earthquakes and eruptions of the nearby Mount Etna.
It was originally constructed in 1078-1093, on the ruins of the ancient Roman Achillean Baths, by order of Roger I of Sicily, who had conquered the city from the Islamic emirate of Sicily.
At the time it had the appearance of a fortified church (ecclesia munita).

In 1169 it was almost entirely destroyed by an earthquake, leaving only the apse area intact.
Further damage was caused by a fire in 1169, but the most catastrophic event was the 1693 earthquake, which again left it mostly in ruins.
It was subsequently rebuilt in Baroque style.

Today, traces of the original Norman edifice include part of the transept, the two towers and the three semicircular apses, composed of large lava stones, most of them recovered from imperial Roman buildings.
The cathedral has been destroyed and rebuilt several times because of earthquakes and eruptions of the nearby Mount Etna. It was originally constructed in 1078-1093, on the ruins of the ancient Roman Achillean Baths, by order of Roger I of Sicily, who had conquered the city from the Islamic emirate of Sicily. At the time it had the appearance of a fortified church (ecclesia munita). 
In 1169 it was almost entirely destroyed by an earthquake, leaving only the apse area intact. Further damage was caused by a fire in 1169, but the most catastrophic event was the 1693 earthquake, which again left it mostly in ruins. It was subsequently rebuilt in Baroque style.
Today, traces of the original Norman edifice include part of the transept, the two towers and the three semicircular apses, composed of large lava stones, most of them recovered from imperial Roman buildings.
Catania Cathedral