Around 1510, Leonardo da Vinci (1452-1519) worked with University of Pavia anatomist Marco Antonio dalla Torre (1481-1511), with the intent of producing the finest anatomical treatise ever produced. Yet the two never published their treatise, and the details of their collaboration remains relatively untold in the scholarly work. Why did Leonardo look for a collaboration with a young anatomist in Pavia? Being not a physician, was it legal for him to dissect bodies on his own? Who were the cadavers he dissected before working with dalla Torre? This talk aims to collect the fragmented information surrounding this collaboration, reconstructing this story within a robust narrative and enriching it with relevant biographical information about dalla Torre.