In the midst of World War II, the Exhibition of Modern Brazilian Paintings left Rio de Janeiro, crossed the Atlantic Ocean, and arrived in London. The Exhibition resulted from a donation of 168 artworks by 70 of the most recognized Brazilian Modernist painters, including Tarsila do Amaral, Candido Portinari, Emiliano Di Cavalcanti, and Lasar Segall. The largest collection sent abroad until that time, and still today the most remarkable show of Brazilian art ever displayed in the United Kingdom, was held firstly at the Royal Academy of Arts in London, in the end of 1944, and subsequently toured throughout other seven British galleries until September 1945. As a contribution to the Allied war effort, the funds from its sales were given to the Royal Air Force. It is noteworthy that the Olympic Games planned to be held in London during the 1944 summer were cancelled due to World War II, but a show of unknown paintings from Brazil reached the British capital and was hosted by its most traditional art institution. Notwithstanding its historical relevance and unmatched scale, this event had never been academically investigated. Even though it was publicized as private entrepreneurship, the dissertation proves that the Brazilian foreign service was the main propelling force of the Exhibition and addresses two fundamental questions regarding the episode. In the first place, why did the Brazilian government back a logistically complicated, politically delicate, and time-consuming idea of sending artworks to be displayed in the United Kingdom during the War? Second, how successful was the Exhibition in view of its original goals, specifically those set by Brazilian diplomacy? Conducted by a career diplomat who practices Public Diplomacy, the research pursued, by applying the hermeneutic method and theories of this field and its subset Cultural Diplomacy, to interpret the reconstructed and contextualized object. Based on its findings, the author argues that the initiative was part of a broader diplomatic program developed by Minister Oswaldo Aranha. Aiming at advancing bilateral ties with the United Kingdom, Aranha sought to foster closer relations between Brazilian and British societies. Furthermore, the Exhibition worked as a cultural component of the part in the War played by Brazil, the only Latin American nation to deploy an important contingent 25,000 troops to fight on the European front. Both the military and artistic contributions must be understood as diplomatic attempts to amass international prestige and reposition Brazil in the postwar emerging order. Having consolidated its regional leadership, the nation aspired to be perceived as a global player that shared the prevailing Western values and aesthetics. The research further claims that the initiative was intended and managed to achieve a substantial impact on views about Brazil, by means of conveying a well-planned message of solidarity, modernization and artistic prowess, which was consistent with the country s diplomatic goals and attuned to Britain s wartime mindset. It focuses on the developments between the period in which Oswaldo Aranha was appointed as Brazilian minister of foreign affairs (1938 1944) and the end of World War II (1945), in order to situate the Public Diplomacy aspects of the Exhibition within Brazil s foreign relations. It thus strives to demonstrate that decades before the coining of the concept to this day discussed mostly between North American and European scholars Brazilian diplomacy was able to conceive and execute an initiative in line with the twenty-first-century state-of-the-art Public Diplomacy. It achieved unprecedented press coverage; high attendance that included influential figures within local society; the entrance of at least 25 Brazilian paintings into important British collections; and the sale of around 80 artworks in benefit of the Royal Air Force. Despite these resounding short-term successes, the lasting effects on Brazil s reputation were arguably mitigated by the diplomatic shift after the end of the War. The revision of the Brazilian foreign policy that followed the replacement of Oswaldo Aranha and President Getulio Vargas impeded the sustaining of the Exhibition s reputational impacts for a longer period, which is a most coveted goal of Public Diplomacy.It is significant that no other show of Brazilian art in the United Kingdom would ever emulate the Exhibition magnitude, devised in the challenging context of War. The coherence between narrative and diplomatic objectives, the powerful and tailor-made message and its appeal to receptors, the involvement of non-official players as well as the high-level political support made the Exhibition, in the author s evaluation, a role model for the cultural category of Public Diplomacy avant la lettre. First of all, the Brazilian government had clearly defined its foreign goals, with stepping up its political stature on the world stage being the first priority. Furthermore, the Ministry of Foreign Affairs was able to develop a solid judgment of Brazil s own international stance, of its reputation among British society, and of the United Kingdom s cultural environment. Hence, it was accordingly defined a compelling narrative compatible with the emerging hegemonic values in the West. In this sense, the choice of the modern idiom and its cosmopolitanism to represent Brazilian art abroad suited the radical aesthetic rupture that would mark the victors new artistic patterns. In addition, the underlying message of the initiative, the solidarity with distant brothers-in-arms well represented by the Royal Air Force, a symbol of British pride in those dramatic times of War was extremely attractive and efficient. The combination of top-tier political backing, without which it would not have been possible to accomplish the feat of sending the artworks across the ocean, and the participation of nongovernmental cultural figures, lending credibility to the initiative, made the Exhibition a successful case of outreach. Finally, the engagement of key Brazilian and British individuals and institutions was the result of a two-way Public Diplomacy action, which involved listening to the receiver and conveying a world-class, coherent, and appropriate message, aligned with and serving diplomatic objectives. By uncovering and studying the Exhibition, the research will hopefully trigger interest in the identification of a Brazilian strain of Public Diplomacy whose discussion is still very incipient among Brazilianists and researchers in general with its own subjects and methods, thus contributing to further this field s theoretical development. A desired indirect outcome of the dissertation is thus to foster an academic concern about a Brazilian distinctiveness in the field, with regard not only to themes and objects of study but also by developing new and useful analytical contributions to the theoretical debate and to the diplomatic praxis. The work sheds light on these Public Diplomacy aspects and contributes, through a relevant case study, to incorporate them into the studies of Brazilian diplomacy. The advantages for Brazil of valuing and perfecting its congenital aptitude for Public Diplomacy are many and evident. As a regional power with limited economic and military assets, its place on the international stage benefits greatly from its capacity to persuade and captivate foreign societies. By doing so, Brazil has better conditions to deal with more powerful nations, to function as a bridge between developed and developing countries, to add value to its products, to receive investments, students, and tourists, to participate in global forums, to shape and influence agendas, and to ensure better treatment of its citizens abroad. Brazil s traditional social consensus around pacifism, embodied in its constitution, and its historic reliance on multilateralism reinforce the convenience of the country s scholars and practitioners advancing Public Diplomacy theory and praxis.