We learned with grief that Giles Constable passed on January 17 of 2021, 91 years old. After teaching during three decades at the University of Harvard from 1958 on, he was awarded the prestigious chair of professor in the School of Historical Studies at the Institute for Advanced Studies in Princeton in 1985. It is there that he organised, as a member of our Commission, a succesful colloquium on ‘La tradition des documents diplomatiques’ (published by A. J. Kosto – A. Winroth, Charters, Cartularies, and Archives: The Preservation and Transmission of Documents in the Medieval West, Toronto, Pontifical Institute of Medieval Studies, 2002). He was an influential explorer of the religious and cultural history of the twelth century, the 12th and 14th century crusading, the origins of monastic tithes, the Benedictine reform of the twelfth century, the history of Cluny. His kindness inspired many talented young scholars, and promoted their careers. In respect for his explicit wishes we have limited to this short, but sincere notice.