Summary To celebrate the centenary of the Union Académique Internationale (UAI) the present volume brings together diverse studies, essays and testimonies offering as many different viewpoints on the history, the realisations and the perspectives of this remarkable institution. In 1919, just after the end of the Great War, a first group of institutions active in the 'Humanities' strove for lasting peace and decided to collaborate unanimously towards the realisation of a number of large projects in the fields of philology, archaeology, historiography and social sciences. The initiative for this international union of academies (or equivalent institutions) was taken by two prominent figures of the Institut de France, members of the Académie des Inscriptions et Belles-Lettres: the Hellenist and archaeologist Théophile Homolle (1848-1925) and his colleague archaeologist Edmond Pottier (1855-1934), curator of the Louvre museum. The definition of the UAI as a 'Republic of Scholars" dates back to 1939 when the Belgian Hellenist Joseph Bidez, one of its founding fathers, celebrated the institution's 20th anniversary, thus making a clear reference to the elegant title "République des Lettres" which in the 18th century designated the cordial network between scholars and humanists belonging to the most diverse nations. A centenary offers the occasion to reflect on the direction one is going and on the ways chosen to achieve one's goals. The different views on the history of the UAI, its realisations and its visions for the future presented in this volume will surely contribute to a better understanding of the nature and the importance of this venerable and valuable institution now celebrating its hundredth birthday. TABLE OF CONTENTS Foreword - Didier Viviers Excellence through Collaboration - Samuel N.C. Lieu The Union Acadmique Internationale, a Laboratory of Scientific Diplomacy in the Interwar Period - Renaud Bardez & Kenneth Bertrams Interpreting the Creation of the UAI within the Context of the International Peace Movement in the Early Twentieth Century: From Wiesbaden 1899 to Paris 1919 - Tae-Jin Yi The First Projects of the Union Acadmique Internationale - Aurore Duriau Thirty Years of Service (1989-2019) - Jean-Luc De Paepe Views from Past Presidents - Madeline Caviness, Shaul Shaked, Agostino Paravicini Bagliani, Miklós Maróth, Janusz Koz?owski & Øivind Andersen CIPSH and its Relations with UAI and UNESCO - Luiz Oosterbeek The Union Acadmique Internationale, the Long Term, and the Humanities - François De Callataÿ Annexes: Introduction to the Historical Documents - Pierre Jodogne History of the Union Acadmique Internationale: From its Origin to 1950 - Joseph Bidez & Victor Tourneur Letter from Waldo G. Leland Read During the 21st Session of the UAI in 1947 The Fiftieth Anniversary of the Union Acadmique Internationale (43rd Session of the UAI, 1969) - Kazimierz Kumaniecki An Assessment of 75 Years of Academic Cooperation and Prospects for the Future - Gerard Verbeke List of UAI Presidents and Secretaries List of UAI Projects List of UAI Member Institutions