But under Gregory IX—whose former name was Ugolino, and who was elevated from the bishopric of Ostia to the pontificate, 1227, an old man, but still bold and resolute—the fire, which had been long burning in secret, burst into a flame.[104] In the year 1227 the pontiff excommunicated the emperor, who still deferred his expedition to Palestine; but without proceeding in due form of ecclesiastical law, and without regarding the emperor’s excuse of ill health. In the year 1228 the emperor sailed with his fleet to Palestine; but instead of waging war as he was bound to do, he made a truce with Saladin on recovering Jerusalem. While he was absent the pontiff raised war against him in Apulia, and endeavoured to excite all Europe to oppose him. Therefore Frederick hastened back, in the year 1229, and after vanquishing his enemies, made his peace with the pontiff in the year 1230. But this peace could not be durable, as Frederick would not submit to the control of the pontiff. Therefore, as the emperor continued to press heavily on the republics of Lombardy, which were friendly to the pontiff, and transferred Sardinia, which the pontiff claimed as part of the patrimony of the church, to his son Enzio; and wished to withdraw Rome itself from the power of the pontiff; and did other things very offensive to Gregory—the pontiff, in the year 1239, again laid him under anathemas; and accused him to all the sovereigns of Europe of many crimes and enormities, and particularly of speaking contemptuously of the Christian religion.
The emperor, on the other hand, avenged the injuries that he received, both by written publications and by his military operations in Italy, in which he was for the most part successful; and thus he defended his reputation, and also brought the pontiff into perplexity and difficulty. To rescue himself, in some measure, in the year 1240 Gregory summoned a general council to meet at Rome, intending to hurl the emperor from his throne by the united suffrages of the assembled fathers. But Frederick, in the year 1241, captured the Genoese fleet, which was carrying a great part of the fathers to the council at Rome, and seizing as well their treasures as themselves, he cast them into prison. Broken down by these calamities, and by others of no less magnitude, Gregory shortly after sank into the grave.
The successor of Gregory, Goffredo Castiglione of Milan, who assumed the name of Celestine IV, died before his consecration; and after a long interregnum, in the year 1243, Senibaldi, a Genoese, descended from the counts Fieschi, succeeded under the pontifical name of Innocent IV, a man inferior to none of his predecessors in arrogance and insolence of temper. Between him and Frederick there were at first negotiations for peace; but the terms insisted on by the pontiff were deemed too harsh by the emperor. Hence Innocent, feeling himself unsafe in any part of Italy, in 1244 removed from Genoa to Lyons in France; and the next year assembled a council there, in the presence of which, but without its approbation (whatever the Roman writers may affirm to the contrary), he declared Frederick unworthy of the imperial throne.
[1244-1274 A.D.]
This most unrighteous decision of the pontiff had such influence upon the German princes, who were infected with the superstition of the times, that they elected first Henry, landgraf of Thuringia, and on his death William, count of Holland, to the imperial throne. Frederick continued the war vigorously and courageously in Italy, and with various successes, until a dysentery terminated his life in Apulia, on the 13th of December, 1250. On the death of his foe, Innocent returned to Italy in the year 1251. From this time especially (though their origin was much earlier) the two noted factions of Guelfs and Ghibellines, of which the former sided with the pontiffs and the latter with the emperors, most unhappily rent asunder and devastated all Italy.