A Saint and patriarch. He was the 25th patriarch of Alexandria (446-454). Our best reference about his life is the Coptic version of the History of the . He was a disciple of Cyril of Alexandria and a vigorous opponent of Nestorian doctrines.

also argued against the Nestorian but he was condemned by a of bishops headed by Flavian, Bishop of Constantinople, on 8 November 448. asked for support from Dioscorus. A was assembled in Ephesus in 449.

Here, a Christological formula based on the Twelve Anathemas of Cyril was edited. But this caused confusion. The of Dioscorus is Orthodox, but at Chalcedon he used the same distinction as Eutyches: “I accept the phrase ‘from two natures’ but not ‘the two natures.’” Dioscorus was also a writer.

We have an encomium on Macarius Bishop of Tkow, which survives in two Coptic , Sahidic and Bohairic. To him also is attributed a letter to Sapianus, another to St. Shenute, and some fragments. The Syriac tradition attributes to him several works that reflect his theological dogma.