Realizing how untenable his position in Rome was growing, Innocent IV secretly and hurriedly withdrew, fleeing Rome on 7 June 1244. Traveling in disguise, he made his way to Sutri and then to the port of Civitavecchia, and from there to Genoa, his birthplace, where he arrived on 7 July. On 5 October, he fled from there to France, where he was joyously welcomed. Making his way to Lyon, where he arrived on 29 November 1244, Innocent was greeted cordially by the magistrates of the city. Innocent now found himself in secure surroundings and out of the reach of Frederick II. In a sermon preached on 27 December 1244, he summoned as many bishops as could get to Lyon (140 bishops eventually came) to attend what became the 13th General (Ecumenical) Council of the Church, the first to be held in Lyon. The bishops met for three public sessions: 28 June, 5 July, and 17 July 1245. Their principal business was to subjugate the Emperor Frederick II. First Council of Lyon The First Council of Lyon of 1245 had the fewest participants of any General Council before it. However three patriarchs and the Latin emperor of Constantinople attended, along with about 150 bishops, most of them prelates from France and Spain. They were able to come quickly, and Innocent could rely on their help. Bishops from the rest of Europe outside Spain and France feared retribution from Frederick, while many other bishops were prevented from attending either by the invasions of the Mongols (Tartars) in the Far East or Muslim incursions in the Middle East. The bishop of Belgorod in Russia, Peter, attended and provided information on the Mongols via the Tractatus de ortu Tartarorum. In session, Frederick II's position was defended by Taddeo of Suessa, who renewed in his master's name all the promises made before, but refused to give the guarantees the pope demanded. Unable to end the impasse Taddeo was horrified to hear the fathers of the Council solemnly depose and excommunicate the Emperor on 17 July, while absolving all his subjects from allegiance. After Lyon The political agitation over these acts convulsed Europe. The turmoil relaxed only with Frederick's death in December 1250, which removed the proximate threat to Innocent's life and permitted his return to Italy. He departed Lyon on 19 April 1251, and arrived in Genoa on 18 May. On 1 July, he was