In 1401 a young man named Michael of Rhodes joined the Venetian navy as a lowly galley oarsman. Over the next four decades, he sailed on more than 40 voyages and took part in five major sea battles, rising through the ranks to become a trusted galley commander.
Michael documented his life and knowledge in a remarkable manuscript. Only recently rediscovered, it chronicles Michael's service record and includes more than 200 pages of commercial and calendrical computations, a beautifully illustrated section on astrology, some of the earliest surviving portolan aids to navigation, and the world's first known treatise on shipbuilding.