The article deals with the analysis of hypothesis that the prominent Old Russian thinker Ilarion-Rusyn (XI c.) was participating in Russian annals. The subject of the analysis are mainly those circumstances, that could substantiated this hypothesis.
Key words: biography of Ilarion, “Sermon on Law and Grace”, ancient annalistic code, “Primary Chronicle”, “learned detachment” of Yaroslav the Wise, historiosophy, historiography.