abbots were deposed for unworthiness, and some mendicant orders were suppressed. On the other hand, the two new orders of Dominicans and Franciscans were approved. There had been several lengthy vacancies of the Holy See, most recently the sede vacante that had lasted from the death of Clement IV, 29 November 1268, until Gregory's election, 1 September 1271. The council decided that in future the cardinals should not leave the conclave until they had elected a pope. This decision was suspended in 1276 by Pope Adrian V, and then revoked by Pope John XXI. It has since been re-established, and is the basis of present legislation on papal elections. Catholic teaching on Purgatory was defined for the first time. Finally, the council dealt with the Imperial throne, which Alfonso X of Castile claimed. His claim was disallowed by the Pope, and Rudolph I was proclaimed King of the Romans and future emperor on 6 June 1274. See also Contra Errores Graecorum History of Lyon Bagimonds Roll Theological differences between the Catholic Church and the Eastern Orthodox Church Ecclesiastical differences between the Catholic Church and the Eastern Orthodox Church Niccolò and Maffeo Polo Notes References [in Latin] 657-658 External links Catholic Encyclopedia: "Lyon, Second Council of" Norman P. Tanner, editor Decrees of the Ecumenical Councils, Second Council of Lyon: Zelus fidei and the conciliar constitutions, including the three post-conciliar constitutions Second Council of Lyon 1274 in Europe 1270s in France Lyon 2 Lyon 2 Filioque Medieval Lyon Lyon 2 Christianity in Lyon Michael VIII Palaiologos Byzantine Empire–Holy See relations