In the meantime, Gregory IX redoubled his efforts to save the Guelf party from ruin. He saw, with alarm, an emperor, master of the Two Sicilies and of Germany, on the point of vanquishing all resistance in upper Italy. He anticipated that this monarch, whose Mussulman soldiers were constantly passing through the states of Rome, would escape the influence of the church, and soon evince no respect whatever for a religion which he was accused of not believing. Gregory had recourse to the two maritime republics of Venice and Genoa, which, in general occupied with their conquests and commerce in the East, seldom took any part in the politics of Italy. He represented to them that they would be soon deprived of the freedom of the seas, if they did not make some effort to save the champions of liberty and of the church in Lombardy. He at length obtained their agreement to contract an alliance with the four only surviving cities of the league of Lombardy; and finally, towards the beginning of the year 1239, he fulminated another sentence of excommunication against Frederick. This had a greater effect than Gregory ventured to hope. A considerable number of nobles of Guelf origin, seduced by court favours, had been won over to the imperial party. They perceived that, after the anathema of the pope, the emperor distrusted them. The marquis d’Este and the count di San Bonifazio were even warned that their heads were in danger, and they made their escape from the imperial camp; all the other Guelf nobles followed their example, and the Guelf cities gained captains habituated to arms and familiarised with higher ideas of politics.