Bruno Messerli was a pioneering geographer and an exceptional person. Although he spent almost all of his long academic career – more than six decades from student to Professor Emeritus – based at the Institute of Geography at the University of Bern, his impacts have gone far beyond Switzerland and geography. Bruno's doctoral and postdoctoral research, from 1958 to 1976, focused on the glacial and post-glacial history of the mountains around the Mediterranean and down into the Sahara – a focus on (past) glaciers and arid mountains to which he returned soon before retirement during his last field projects (1988–1996) in the high Andes of the Atacama. In between, he played leading roles in many major interdisciplinary projects. The first of these was the Swiss element of UNESCO's Man and the Biosphere (MAB) Programme, which he directed, together with Paul Messerli (unrelated) from 1977 to 1986. Overlapping this, he was the co-manager of the United Nations University's (UNU) project on Highland-Lowland Interactive Systems (later, Mountain Geoecology and Sustainable Development; 1979–1991), together with Jack Ives. Jack and Bruno's partnership had started earlier, in the International Geographical Union's Mountain Commission; they alternated as chairs from 1972 to 1996. A primary outcome of the UNU work in Nepal was their co-authored book The Himalayan dilemma: Reconciling development and conservation (1989), which used detailed field research to analyse the “Myth of Himalayan Degradation.” Bruno continued this work with Thomas Hofer, resulting in the 2006 book Floods in Bangladesh: History, dynamics and rethinking the role of the Himalayas. The impact of the Messerli-Ives partnership went well beyond academia. The work they led in Nepal showed that many of the myths about Himalayan degradation, often quoted by politicians and in the media, were incorrect. In the early 1990s, their focus turned to the global stage, when they recognised–together with the Swiss Agency for Development and Cooperation–that the Rio Earth Summit in 1992 would present a unique opportunity to get mountains on the stage. The result of concerted diplomatic and scientific effort was Chapter 13, on “Sustainable mountain development,” in “Agenda 21,” the plan of action deriving from this global meeting. Bruno continued to play a key role in keeping mountains on the global agenda, including the publication (again with Jack Ives) of Mountains of the world: A global priority in 1997 and a series of reports until 2002. Key outcomes of these continuing efforts were the declaration of the year 2002 as the International Year of Mountains and, since then, 11 December as International Mountain Day. In addition to his activities in research and advocacy, Bruno played many other important roles. At the University of Bern, he was a gifted teacher and mentor who enthused thousands of students and supervised 35 PhD and 104 Master's theses, and served as Rector of the University in 1986–7. He had national roles with the Swiss University Conference, Research Council and Swiss National Science Foundation. After his official retirement in 1996, he became President of the International Geographical Union (1996–2000) and Co-Director of the International Geosphere-Biosphere Programme's project on Past Global Changes (PAGES; 1996–2001), and then continued in other roles with the International Foundation of Science and the International Centre for Integrated Mountain Development (ICIMOD), which he had helped to establish in 1983. Bruno's remarkable contributions were recognised in many ways. In Switzerland, he was awarded the Doron Prize and the Marcel-Benoist Prize and, internationally, numerous awards–including the Founder's Medal of the Royal Geographical Society (with IBG), the Mountain Award of the King Albert I Memorial Foundation, and the Prix Vautrin Lud, the “Nobel of Geography”–as well as honorary doctorates from the University of Innsbruck and the Free University of Berlin. All of the above underlines Bruno's energy and remarkable professional achievements. Yet he was also a man who was deeply committed to his family–his wonderful wife, Beatrice, to whom he was married for 55 years, his four children, and his nine grandchildren–and he enjoyed the mountains, music, and good food and drink. Though his roots were in the Swiss Canton of Bern, he was a consummate professional geographer and interdisciplinary scientist who has made a real difference to thousands of people around the world and, through his publications and the work of his family and everyone else he mentored and worked with, will continue to do so.