Goals. The article aims to consider some key historical milestones and achievements in Buryatia’s nation-state building for over 100 years. The paper analyzes the conditions for the emergence of Buryat-Mongolian autonomy, and the factors that prompted reorganizations of the Republic’s political structure in the context of changes witnessed in the nationwide political agenda. Special attention is paid to the contribution of the Republic to the Great Victory, certain analytical emphases be laid on present-day challenges, achievements and development prospects. Materials and methods. The work examines unpublished documents stored at the State Archive of the Russian Federation, Russian State Archive of Sociopolitical History, and State Archive of Buryatia. The principles of historicism and consistency prove instrumental enough in reconstructing the process of nation-state building in Buryatia, identifying specific features, and tracing general trends of state development in the Republic’s political life. Results. On 30 May 1923, the Presidium of the All-Russia Central Executive Committee decided to unite Siberian and Far Eastern autonomous domains (oblasts) of Buryat-Mongols into one autonomous socialist Soviet republic centered around the city of Verkhneudinsk. It is then and there that the statehood of Buryat-Mongols — consolidated by a single territory, economic integrity, and historical ties of all resident peoples — was proclaimed. The shaping and rapid development of industries in the Republic, transformations in agriculture, education and health care converted the territory of Buryatia into a strong supporting point that would render every possible assistance to the nation during the Great Patriotic War. The post-war years up to the 1960s and early 1970s became a period of progressive development in all spheres of life. At the all-Union level, merits of the Republic were distinguished with the Order of Lenin (1958), Order of Friendship of Peoples (1972), and Order of the October Revolution (1973). Events of the late 1980s and the subsequent collapse of the USSR served as a test of state viability to the Republic. The economic depression led to an unprecedented deterioration of the social situation which could actually result in a severest interethnic conflict. However, the accumulated experiences of cross-cultural interaction, flexible administrative and managerial systems, high educational and scientific levels of the population, and a unified language environment proved instrumental in neutralizing negative trends and strengthening constructive ones — as part of interethnic dialogue within the new statehood of Russia. Despite the complicated processes of the 1980s–1990s, Buryatia confirmed its loyalty to the principles of federalism and integrity of Russia. Another important milestone was the 1994 adoption of the Constitution of the Republic of Buryatia. Over the past hundred years, the Republic has developed as a major political/legal entity of the Russian Federation — in cultural, economic, and other aspects. Nowadays, the peoples of Buryatia — regardless of faith and ethnic identity — join efforts to develop public economy and culture, shape a common destiny of the Republic and the country on the basis of friendship, harmony, and mutual understanding.