Not just someone's opinion

Camoccio map of Negroponte, published 1571-4,
based on sources from 1460-1470.

In 1459, in Venetian dating, 1460 in ours, Venice realized the inadequacy of its sources of information about its overseas and mainland territories. It sent out a decree as follows:

Consilio di Dieci, Misti, v. 15, 198r [197r]

1459(=1460), Feb. 27

In the matter of cities, forts and provinces which by the grace of God are subject to our dominion, when we deliberate about those places, since there is no specified person who can give detailed information concerning location [ . . . . ] length and width, boundaries, what the neighboring areas are and how far away they are, if information is sought from various people at various times [ . . . . ] because either they think it is that way or they would like it to be that way.

Whence, for every good reason, there must from now on be provided in the chancellery of the state or in the apartment of our council of Ten, giving their true image and form, representations of all of our cities, lands forts, provinces and places so that anyone wanting to deliberate and make decisions about them may have a true and detailed written account, and not just someone's opinion.

Vadit pars. By the authority of this council it is to be written to all rettori of cities, lands and forts belonging to us and ordered that, having formed a council made up of selected citizens of that region and of other practical and educated men, they shall put together information about the land, the location, and district, identifying both to east and west the forts, rivers, open spaces, and distances from place to place and the places neighboring us and the distances between them and draw them diligently in a orderly way to be examined by learned and practical men to see whether it is well and properly done. Once they have done this they are to send that picture [for the use of] our dominion.

The Latin text is here and the original document can be found here in the ASVe Deliberatione misti R. 15.

Pierre MacKay translated and has been working on this material, and the rest of the blog is his:

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In early 1460, having watched the Ottomans take over Athens and Mistra, the Venetians had to expect that their own outposts would soon be targeted. Their sense of urgency can be seen in the way that magistracies such as the Council of Ten found themselves deliberating over a wide range of subjects beyond their normal remit, including the defense of distant parts of the Venetian Empire. Exasperated with the responsibility of deciding policy for territories about which they knew very little, they produced this decree requiring the rettori of Venice's possessions to supply them with accurate maps and descriptions of each location. 

 

The language of this document is delightful for its directness (an advantage given to a secret organization). The impatience of the Council breaks through the tortuous and deeply parenthetical style. The Dieci complain that when random informants (aliquibus) are asked about Venice's distant possessions, their answers are valueless since they are based only on what the informants think to be the case or what they wish might be the case (aut ita putant aut ita vellent).

What the Dieci insist on is clear, detailed written evidence and not just someone's opinion (et non ad opinionem alicuius). It is the local residents (people, that is, who know what they are talking about) who are to be called on for their evidence and the observations of experienced men (e. g., traders and seafarers) are to be collected for the making of a detailed map (pictura). I have difficulty in interpreting the syntax of “designatione ordinato” (the letters are quite clear in the image) but it may conceal some idea like “drawn to scale.”

Finally, note that the maps are to be inspected by local experts (doctis et praticis) so that the Dieci have some assurance that they can be relied on.

We have an indication that this sort of mapping was done at once, at least for places on the front line against the Ottomans. Twenty months after this decree, the Dieci voted confidently (14, 0, 3) on a detailed program for improvements in the defences of Negroponte, and their recommendations are precise and reasonable. They seem to have had, for their deliberations, a very good representation of the city of Negroponte and its surroundings. Perhaps we are dealing here with one of the earlier maps produced in accordance with the decree of 1460. If so, it is quite likely to be the original on which Giovanni Camoccio based the map he drew in 1571—74. This raises the tantalizing hope that there may be an as yet unrecognized collection of such maps waiting to be discovered in some Venetian archive.




Thanks to Karen Barzman whe informed me of references to this decree and initiated the search on Serenissima that produced a citation from the History of Cartography, and thanks as always to those at the Archivio di Stato di Venezia who have created tools for a revolution in Venetian historical studies.

See also: Emanuele Casti, "State, Cartography, and Territory in the Venetian and Lombard Renaissance," in D. Woodward, G. M. Levis, (eds.) The History of Cartography, University of Chicago Press (Chicago 2007) Vol. 3: 874-908, esp. 878n11, but note that Casti restricts the application of this decree to the lands of the terra ferma, a restriction which is nowhere state dor implied in the decree.