Frederick barricaded the bridge over the Tiber, and was duly crowned in St. Peter's. But the rite was scarcely finished when the Romans, who had assembled in arms on the Capitol, dashed over the bridge, fell upon the Germans, and were with difficulty repulsed by the personal efforts of Frederick. Into the city he did not venture to pursue them, nor was he at any period of his reign able to make himself master of the whole of it. Finding themselves similarly baffled, his successors at last accepted their position, and were content to take the crown on the Pope's conditions and depart without further question. [Sidenote: Memorials of the Germanic Emperors in Rome.] [Sidenote: Of Otto the Third.] Coming so seldom and remaining for so short a time, it is not wonderful that the Teutonic Emperors should, in the seven centuries from Charles the Great to Charles the Fifth, have left fewer marks of their presence in Rome than Titus or Hadrian alone have done; fewer and less considerable even than those which tradition attributes to those whom it calls Servius Tullius and the elder Tarquin. Those monuments which do exist are just sufficient to make the absence of all others more conspicuous. The most important dates from the time of Otto the Third, the only Emperor who attempted to make Rome his permanent residence. Of the palace, probably nothing more than a tower, which he built on the Aventine, no trace has been discovered; but the church, founded by him to receive the ashes of his friend the martyred St. Adalbert, may still be seen upon the island in the Tiber. Having received from Benevento relics supposed to be those of Bartholomew the Apostle[336], it became dedicated to that saint, and is now the church of San Bartolommeo in Isola, whose quaintly picturesque bell-tower of red brick, now grey with extreme age, looks out from among the orange trees of a convent garden over the swift-eddying yellow waters of the Tiber. [Sidenote: Of Otto the Second.] [Sidenote: Of Frederick the Second.]