Considering the role played by Venice during and after the Fourth Crusade, it is not surprising that Venetian sources are among the most important and abundant for the history and prosopography of the Byzantine world – Romania as it was called at the time – during the thirteenth century. That does not mean, however, that they are always easy to handle or will always answer the questions that are the most vital for the prosopographer: obviously Venetians are over-represented among the various groups active in the Aegean at the time. Moreover, although Venetian archives are rightly famous, the documentation remains rather scarce until the middle of the century, and with some exceptions official records do not really develop before its last decade.1 Historiographic texts exhibit other difficulties: the very limited scope of my chapter is to present them and what they can and cannot offer to the history of individuals.