The potter's clay of Ischia served for the potteries of Cumae and Puteoli in ancient times, and was indeed in considerable demand until the catastrophe at Casamicciola in 1883.
Of these Ischia and Procida, close to the northern headland of the Bay of Naples, are of volcanic origin, as is the case also with the more distant group of the Ponza Islands.
These are three in number Ponza, Palmarola and Zannone; while Ventotene (also of volcanic formation) is about midway between Ponza and Ischia.
In June 1809, during his campaign against Austria, Sir John Stuart with an Anglo-Sicilian force sailed northwards, captured Ischia and threw Murat into great alarm; but on the news of the Austrian defeat at Wagram Stuart sailed back again.
It subsequently fell into the hands of Neapolis, and remained so until the time of Augustus, who took it in exchange for Aenaria (Ischia) and often resided there.