The catacombs influenced the Roman Church in another way. There are none but martyrs' names among the liturgic commemorations of the confessors of the faith (whom we now call "saints"); and these names loudly proclaimed in the _Canon_--in the solemn portion--of the eucharistic services which were held at their graves, not only on the day of deposition but on many other stated days besides, were the nucleus of that long line of "_canonised_" saints which figures in the modern calendar. When, after the "Peace," churches began to cover the city, the very grave of the confessor became the nucleus of the Christian edifice--that confession or sunk tomb which is the central point of the Roman basilica. And as the liturgy had been celebrated on the stone slab which closed the grave so when churches were built the altar was placed over the confessor's tomb: "I saw under the altar the souls of those that had been slain for the word of God, and for the testimony which they held." [Illustration: LIBRARY OF THE HOUSE OF DOMITIAN ON THE PALATINE Painted on a stormy day. The sombre scene of the ruined Library in the Palace of the Flavian Emperors suggests the ruin of classical learning which followed on the introduction of Christianity. The mother of Domitian's two nephews, whom he had intended to designate as his heirs, was martyred as a Christian, and their cousin of the same name--Flavia Domitilla--founded the catacomb of the Flavian House.] Thus subterranean Rome prepared, as in the hidden working of a mine, not only many affirmations of the faith which was to assert itself in the light and replace the religion of classical Rome, but also the sanctuary of those great basilicas which were to spread over the surface of the city as soon as the Christians, in no real but nevertheless in a highly suggestive sense, "came up from the catacombs." The catacombs are the link between pagan Rome "drunk with the blood of the saints" and the Christian Rome which arose in the imperial city from the ashes of her martyrs. The pagan city on the seven hills as truly sunk into the grave with the bodies of the Roman martyrs as Christian Rome eventually took possession of the same _urbs septicollis_ by carrying her dead into it. CHAPTER IV ROMAN REGIONS AND GUILDS The regions and the guilds of Rome illustrate two contradictory tendencies running parallel throughout the administrative history of the city, the one towards division and separation as first principles of organisation, the other towards union and centralisation as measures of strength. These antagonistic elements which we find at the very dawn of Roman history were at once utilised as factors in the new commonwealth.