The article is devoted to the analysis of such a phenomenon as the emergence, development, and transformation of the «Bulgar idea» among the Vaisovites along with the inception and evolution of the teachings and practical movement of the Vaisovites in the early 1870s — early 1920s. The choice of this a half-century chronological segment is conditioned, on the one hand, by specific historiographic gaps; on the other, by the presence of autochthonous and relevant written evidence, speaking in the voice of the «Vaisovites» themselves. The events related to the so-called «neo-Bulgarists» of the late 20 — early 21 centuries, relatively well studied by the works of V. Schnirelmann, T. Uyama, and S. Cwiklinski are deliberately left outside this article. The article also indirectly touches upon examples of the various manifestations of «Bulgarism» in the Tatar intellectual environment and the historiographic field of the 19th century (covered in the works of M.A. Usmanov, A. Frank, M. Kemper, etc.).