On 15 July 668, Contans II was assassinated in his bath by his chamberlain, according to Theophilus of Edessa, with a bucket. His son Constantine succeeded him as Constantine IV. A brief usurpation in Sicily by Mezezius was quickly suppressed by the new emperor. Constantine IV was Byzantine Emperor from 668 to 685. His reign saw the first serious check to nearly 50 years of uninterrupted Islamic expansion, while his calling of the Sixth Ecumenical Council saw the end of the monothelitism controversy in the Byzantine Empire; for this, he is venerated as a saint in the Eastern Orthodox Church, with his feast day on September 3. He successfully defended Constantinople from the Arabs.