Diodorus, Didymus, and Diomedes were three Christians of Laodicea who, according to the synaxarion, were put to death for confessing Christ during the fourth century. They are commemorated together as a group on September 11, and the tradition preserves little about them beyond the city of their origin and the manner of their death.
By the account followed in the Orthodox synaxaria, the three were natives of Laodicea and suffered in that same city. Sources record that they spread the Christian faith and, on being seized for their confession, were subjected to severe scourging, dying as a result of the flogging. No detailed narrative of their interrogation or of an individual martyr has been handed down, and they are remembered chiefly as a named trio of confessors.
The city called Laodicea is variously located by sources: the Orthodox Church in America records the three simply as 'of Laodicea,' while other martyrologies place them at Laodicea in Syria. Their exact date is not fixed beyond the fourth century, and some Western references describe them as martyrs of unknown date, reflecting how scant the surviving record is.