The Emperor Constantine had a daughter, Constantia, we know from profane history, who was married to Hannibalianus—a thoroughly unprincipled woman, in fact, if we may trust the highly coloured picture drawn of her by Ammianus Marcellinus. She was a demon in human form, a female fury ever thirsting for blood. But though generally called Constantia, her correct name was Flavia Julia Constantina. Of the Constantia of the legend there is no mention by the historical writers of the time; but this is not remarkable if she were, as is represented in the story, a woman who took no part in public life, but lived in retirement, partly because of her disorder, and then because she had embraced the religious life. A further difficulty arises in the account of the martyrdom of SS. John and Paul, her chamberlains. The Acts represent them as subjected to interrogation by Julian himself in Rome, whereas it is quite certain that after he became Emperor he did not set foot in Italy. It will be seen, therefore, that there is here every reason for repudiating the whole story as fabulous, and some would go so far as to say that Constantia, the virgin daughter of Constantine, Gallicanus, John and Paul were all of them mythical characters, creatures of the imagination. But there are certain very good and weighty reasons on the other side for inducing an arrest of judgment. In the first place, close to the basilica and catacomb of S. Agnese is a very interesting and precious circular church, erected by Constantine the Great, at the request of his daughter Constantia, as a thankoffering for her recovery from the distressing disease which had disfigured her and made life a burden to her. This church is, perhaps, the most remarkable specimen we have existing of ecclesiastical architecture of the age of Constantine. It is quite untouched, and is rich with frescoes of the period. But a still more remarkable monument is one quite recently disinterred. It is the house of the martyrs John and Paul, which has existed for centuries buried under the foundations of the great church that bears their names on the Cœlian Hill, a church erected by the one English Pope, Nicolas Breakespeare, in 1158. The discovery of the house is itself a romance. What is known of its early history is this: Julian the Apostate died in 363. The death of John and Paul had taken place in 362. Julian was followed by Jovian, who died in 364, and was succeeded by Valentinian. Now, directly Julian was no more, Byzantius, a senator and a Christian, interested himself in the matter. The recent martyrdom was in all mouths, and it was known that the bodies lay in the cellar of the house. Byzantius had the bodies lifted and placed in a white alabaster or marble box, and converted the upper storey of the house into an oratory.