The conclave assembled at Viterbo at length raised to the vacant chair Teobaldo Visconti, of Piacenza, who was at that time in the Holy Land. On his return to Italy, in the year 1272, he took the name of Gregory X. This wise and moderate man soon discovered that the court of Rome had overreached itself; in crushing the house of Hohenstaufen, it had given itself a new master not less dangerous than the preceding. Gregory, instead of seeking to annihilate the Ghibellines, like his predecessors, occupied himself only in endeavouring to restore an equilibrium and peace between them and the Guelfs. He persuaded the Florentines and Sienese to recall the exiled Ghibellines, for the purpose, as he announced, of uniting all Christendom in the defence of the Holy Land; and testified the strongest resentment against Charles, who threw obstacles in the way of this reconciliation. He relieved Pisa from the interdict that had been laid on it by the holy see. He showed favour to Venice and Genoa; both of which, offended by the arrogance and injustice of Charles, had made common cause with his enemies. He engaged the electors of Germany to take advantage of the death of Richard of Cornwall, which took place in 1271, and put an end to the interregnum by proceeding to a new election. The electors conferred the crown, in 1273, on Rudolf of Habsburg, founder of the house of Austria. The death of Gregory X, in the beginning of January, 1276, deprived him of the opportunity to develop the projects which these first steps seem to indicate; but Nicholas III, who succeeded him in 1277, after three ephemeral popes, undertook more openly to humble Charles, and to support the Ghibelline party. He forced the king of Sicily to renounce the title of imperial vicar, to which Charles had no title except during the interregnum of the empire; he still further engaged him to resign the title of senator of Rome, and the dignity of the signoria, which had been conferred on him by the cities of Lombardy and Tuscany, by representing to him that his power over these provinces was contrary to the bull of investiture, which had put him in possession of the kingdom of Naples.