At some point between 1434 and 1436 a Venetian seaman named Michael of Rhodes decided to create a book containing all the information he deemed useful to his status and occupation as well as interesting for more personal reasons. He probably kept it in his possession until his death in 1445; he copied key sections into a second book in 1444, which another Venetian seafarer, Pietro di Versi, claimed as his own by substituting his own name in the descriptive title (becoming the putative author until recent research revealed that the hand belonged to Michael of Rhodes). The original book also passed into the possession of at least one other Venetian seaman, Giovanni da Drivasto, who used two blank folios to compose a will in August 1473 while aboard a Venetian galley.

Sixteenth- and seventeenth-century scholars, including the famous editor of the voyages of travel and exploration Giovanni Battista Ramusio, copied the section on shipbuilding; nineteenth-century historians would study the medieval manual which emerged from these copies without any understanding of its origins in a book written by Michael of Rhodes. The original manuscript also bears traces of sixteenth-century and possibly later interventions. Federico Patetta owned it in the early twentieth century but by 1945 it had exited his considerable collection to reappear for sale in 1949, 1966 and, finally, 2000. The current owner's willingness to make the manuscript available for study was the catalyst for this three-volume scholarly edition developed under the auspices of the Dibner Institute for the History of Science and Technology (then at MIT), which includes a facsimile, complete transcription and translation, and a collection of nine essays examining Michael of Rhodes, his manuscript and the world which produced them.

The content of Michael of Rhodes's book beautifully illustrates the uses of literacy at the end of the Middle Ages and the early Renaissance. Michael, who was probably born on the Greek island of Rhodes, since he described his arrival in Venice in June 1401, embodied all the possibilities and constraints of a life lived in the Venetian empire. A talented and capable seaman, he competed successfully for work on the Venetian galleys for over forty years. He demonstrated bravery, luck and acumen in the successful navigation of key naval battles, imperial envoys and commercial trading routes, and earned the elected office of armiraio (the highest position to which a non-noble could aspire) for the 1436 merchant convoy to Flanders. Yet as a non-citizen who was also a commoner, Michael of Rhodes enjoyed only limited and fleeting opportunities to compete for the most prestigious and lucrative positions in the Venetian commercial galleys and naval fleet. Despite his receipt of rights to run one of the weighing stations in the steelyard in January 1445, in return for a lifetime of service, his will reveals his economic distress at the end of his life.

To differing degrees, all of the contributors to this project explain Michael of Rhodes's decision to compose his book in relation to his chosen occupation. For some historians, the book was a means for Michael of Rhodes to distinguish himself from other seamen competing for the most sought-after positions on the ships, an expression of individuality as well as self-fashioning. His book made him a learned seaman, no mere labourer but a scholar of ships and waters. For others, Michael of Rhodes was a man who used his pen to explore more personal interests in mathematics, portolans, and shipbuilding while also recording key pieces of information about astrology, medicine, and the liturgical calendar and taking a few pages from his book to keep track of his resumé. Finally, we are presented with the idea that Michael of Rhodes composed his book as a means to further his income, instructing young Venetian nobles new to the sea in the kinds of knowledge they should acquire before holding office, and making copies of his own book to sell to other ambitious seamen who aspired to a similar role. All of these interpretations are present in the essays accompanying this volume and it is to the credit of the collaborative team which put together these volumes that they have not tried to resolve entirely their differences of opinion but allowed them an amicable coexistence.

There is no question that Michael of Rhodes left behind a fairly unique document which captures the uneven process by which knowledge circulated in the early fifteenth century. Pamela Long's excellent overview of the world of Michael of Rhodes raises many of the issues addressed in greater detail in other essays, while Alan Stahl brilliantly uses the Venetian archives to offer a richly detailed account of the ups and downs of his career in relation to other seamen of his generation. Other essays thoroughly explore the role of mathematics (Raffaella Franci), visual images (Dieter Blume), portolans (Piero Falchetta), shipbuilding in theory and practice (David McGee and Mauro Bondioli) and calendrical time-keeping and prognostication (Faith Wallis). Franco Rossi offers a thorough introduction to the history and physical appearance of the manuscript, both in the introduction to volume 2 and in a separate essay in volume 3. Any reader who examines all of these parts together will come away with a rich appreciation of the kinds of knowledge cultivated by Venetians in pursuit of far-flung commercial and overseas empire.

What provisional conclusions might we draw about Michael of Rhodes's goals in pursuing this project? He was clearly curious about theoretical mathematics, well beyond the kind of practical and commercial arithmetic that was absolutely necessary in the world of trade, though not entirely proficient in it. He may have traded in small quantities of pepper, like many seamen in the Eastern Mediterranean. He thought it worthwhile to copy, if rather imperfectly and incompletely, information on the best routes from Venice to England and Flanders, as well as instructions on how to build different kinds of ship. He thought he should know some basic astrology, the dates for Easter, and the best way to avoid drowning and generally to preserve one's health. Towards the end of his life, as he paged through his book, he decided to record the deaths of his first two wives and son, dating them in relation to his list of voyages. There is precious little personal information of this kind, however, throughout the book, bringing to mind Dennis Romano's fascinating essay about why the Venetians (unlike the Florentines) did not write ricordanze. It was indeed a book that could be appropriated by others who found the knowledge it contained useful for their own purposes.

Much like the Sienese peasants of Duccio Balestracci's The Renaissance in the Fields (University Park, PA, 1999) who kept a multigenerational account book in which others wrote down the things they wished to remember in writing, Michael of Rhodes reflects the expansion of literacy and numeracy among artisans in a thriving commercial city. He was no Brunelleschi, Taccola or Alberti, but he was nonetheless a curious mind of the kind we rarely get to encounter from the distance of almost six hundred years. Michael of Rhodes's book offers a fascinating portrait of a world of men, ships and goods in motion, as seen by a man whose most personal statement was a self-invented coat of arms, drawn in the middle of his book, in which a mouse holds a cat. Here, more than anywhere, we see Michael of Rhodes's ambition to grasp his world with a pen in hand. We should be deeply appreciative to the owner of this manuscript; the Dibner Institute; and Long, McGee and Stahl for bringing Michael of Rhodes to life for modern historians.