Called by pope Innocent IV, the First Council of Lyons opened on the 26th of June 1245. It was the thirteenth ecumenical council of the Catholic Church, convened by Pope Innocent IV, and was attended by 150 bishops. The reason for the council was

That the church, through the salutary counsel of the faithful and their fruitful help, may have the dignity of its proper position; that assistance may speedily be brought to the unhappy crisis in the holy Land and the sufferings of the eastern empire; that a remedy may be found against the Tartars and other enemies of the faith and persecutors of the christian people; further, for the issue between the church and the emperor

and was primarily concerned with the dispute the Holy Roman Emperor Frederic II who due to his attempts to suppress the Lombard League, had been excommunicated in 1239 by pope Gregory IX. The council reaffirmed the excommunication of Frederik II and deposed him on counts of perjury, disturbing the peace, sacrilege, and suspicion of heresy.1

The council also addressed clerical discipline, usury, and the persecution of Christians by groups such as the Tatars. Directed efforts toward launching the Seventh Crusade, which was later led by King Louis IX of France, and played a crucial role in shaping medieval European politics and church authority.

• 1. Wilson, Peter H The Holy Roman Empire London Penguin Books 2016. p719.