ArgumentLudwik Antoni Birkenmajer (1855-1929), following along the paths pioneered by Leopold Prowe, Maximilian Curtze, Franz Hipler, and J. L. E. Dreyer, joined them as trailblazers of Copernican scholarship in the nineteenth century. Educated in the classics and mathematics, Birkenmajer began by examining more closely the Cracow background to Copernicus's development and studying his works and annotations in books he owned or read. Birkenmajer contributed many discoveries that eventually became common knowledge, and his studies loomed over Polish research on Copernicus into the 1970s. Focusing on historical context and his original insights, the essay reminds readers of his contributions (sections 1–2), relates them to discussions of Copernicus's precursors (section 3), to the debate about Maragha precedents (section 4), his reading of theUppsala Notebook(sections 2 and 5), and his account of the origin of Copernicus's heliocentrism (section 6). By means of a more critical assessment of his interpretation, the essay revises earlier accounts, rescuing the original insights that mark Birkenmajer's most important contributions to current debates and his efforts to reconstruct Copernicus's path to heliocentrism.