Two Classical Plays Titus Andronicus and Timon of Athens:

There are, however, other aspects of the play that make the time of Caracalla far too early. As it happens, there is in existence a tale called The Tragical History of Titus Andronicus, of which the only known copy was published about a century and a half after Shakespeare's play was written. That copy may, however, be a reprint and the original may have appeared early enough to serve as Shakespeare's source. In the booklet the time is set in the reign of Theodosius, by whom is probably meant the most famous Emperor of that name, Theodosius I. He ruled from 379 to 395, nearly two centuries after Caracalla. When Theodosius died, he left behind two sons, but these, unlike the sons of Septimius Severus (or those in the play), did not compete for the throne. They inherited the co-emperorship in peace, with the elder, Arcadius, ruling the Eastern half from Constantinople, and the younger, Honorius, ruling the Western half from Rome. To be sure, by the time Theodosius was Emperor, Rome was thoroughly Christian and Theodosius himself was particularly pious in this respect, so that the paganism of the play would then become an anachronism. (On the other hand, considering the horrible events that take place in it, the existence of Christianity would be embarrassing.) … surnamed Pius It turns out that there are factions in Rome who want neither son of the old Emperor, but who turn instead to a valiant general ...»