It is the most active volcanic centre in the Aegean Arc, though what remains today is largely a caldera. The name Santorini was given to it by the Venetians in the 13th century and is a reference to Saint Irene. Before then it was called Kallistē ('the most beautiful one'), Strongylē ('the circular one'), or Thera.
The island was the site of one of the largest volcanic eruptions of the last several thousand years when it erupted cataclysmically about 3,500 years ago. The eruption left a large caldera surrounded by volcanic ash deposits hundreds of feet deep, and its effects may have indirectly led to the collapse of the Minoan civilization on the island of Crete, 110 km (70 mi) to the south.
