On 12 October 2021, Prof. Dr. Burkhard Roberg, who was closely associated with the research project History of Councils in all the years of his academic activity, passed away in Bonn at the age of 86. Since his dissertation in Bonn, Die Union zwischen der griechischen und der lateinischen Kirche auf dem 2. Konzil von Lyon 1274 im Jahre 1963, he has repeatedly written about this synod, as well as the 1st Council of Lyon. The monograph Das Zweite Konzil von Lyon (1274) in the series Konziliengeschichte in 1990, the edition on Lugdunense II in the Conciliorum Oecumenicorum Generaliumque Decreta, vol. II/1, 2013 and many pubblications in the Annuarium Historiae Conciliorum as well as other journals show this. Since the Council History Symposium in Thessaloniki in 1976 (second from the right in the picture), he has repeatedly presented the results of his research at the meetings of the Society for the History of Councils, as long as his health allowed him to do so. The circle of colleagues in the research project has lost a friend and respected scholar in Burkhard Roberg; future publications on the Lyon Synods will build on his studies.