This time it was Charles, and not the Pope, whose success was the obvious fact. Whether the Pope interceded for the last of the Hohenstaufens or approved his execution, is a matter of some doubt. But Charles was now elected senator of Rome for life, and Clement offered no opposition to this violation of the original agreement. Moreover, on Clement's death (November, 1268), the divisions among the Cardinals assembled at Viterbo prolonged the vacancy in the papal chair for nearly three years. During that time Charles developed the most ambitious schemes. With the Ghibelline position he took up the Ghibelline aims. Thus the papal plans for reviving the Crusades were nothing to him, but he desired to obtain for himself the crown of Jerusalem; and since Constantinople had been recovered by the Greeks in 1261, while on the one side he make a treaty with the Latin ex-Emperor, Baldwin II, whereby the reversion of the Byzantine throne should go to the King of Sicily, on the other side the papal project for an union of the Greek and Latin Churches was an obstacle to his hostile design. Charles, in fact, began to equip an expedition against Constantinople. Louis IX for the moment checked his brother's schemes and took him off on the crusade from which Louis himself was not to return. The diversion of the expedition from Palestine or Egypt to Tunis is generally attributed to the influence of the King of Sicily, whose Norman predecessors had once held the north coast of Africa: but this charge can scarcely be maintained, for the crusade thither interfered with his schemes against Constantinople, which were resumed immediately on his return to Europe. [Sidenote: Gregory X (1272-6).]