Auction values in the Venetian Incanti system


During the Middle Age, and especially between 1283 and 1453 (fall of Constantinople), the Republic of Venice introduced new regular maritime routes to connect the city with the rest of the Europe, through the Mediterranean and Black sea to England and Flanders. In total, the Venetian authority built seven (cf. figure 3 and table 1) precise shipping routes. Moreover, a new system of shareholding permitted to share the risks between different acquirers. This system promised a proportional part of the freight for each share: this is the Venetian Incanti system. A security service was introduced to protect maritime routes from potential risks such as piratery. Indeed, this system involved the logical development of the guarding weaponry of each galley (specific ships used for the Incanti). The galleys started to travel in small groups to increase their protection. Protected maritime routes were born. Pirates and corsairs started to quake!

This ingenious system has been especially explored by Doris Stöckly in her thesis work “Le système de l’Incanto des galées du marché à Venise (fin du XIIIe – milieu du XVe siècle)” [1]. The huge database provided by her research appeared to us as a very interesting source of information and a very valuable resource.

After a preliminary exploration of the database, an interesting problematic may be formulated: how was the risk attenuated and distributed across maritime routes by the Venetian  Incanti? Can we identify trends and regular patterns in the Incanti system by representing austere data using GIS technologies?  The goal is to represent the relative importance of the maritime routes on a map in order to support the historical analysis of Doris Stöckly [1]. 

Routes’ name Color on the map Epoch of use (# years in operation)
1 Romania – Black Sea Red 1283-1453 (102 years in operation)
2 Armenia – Cyprus Blue 1294-1453 (35 years in operation)
3 Alexandria Green 1301-1453 (88 years in operation)
4 Beirut Orange 1374-1453 (67 years in operation)
5 Flanders Black 1310-1453 (69 years in operation)
6 Aigues-Mortes Pink 1412-1453 (37 years in operation)
7 Maghreb Yellow 1437-1464 (16 years in operation)

Table 1: List of the seven routes (source).


In order to answer to the problematic of this project, the idea is to use (geo)graphical representation with the will to highlight a certain evolution of these auction’s values for each route over the time.

  • Building the known maritime routes on GIS interface.

By using the Doris Stöckly’s researches, the EPFL’s Digital Humanities lab has developed a complete web-SIG interface to precisely represent these seven routes with some additional information [2]. Based on this overview plus the data available from Stöckly’s work, which contains localisation (longitudes, latitudes) of all the ancient Mediterranean harbors used during the Incanti era, a preliminary task was to build on a GIS shape with these seven routes. This has been done with the software Quantum GIS (QGIS), because its a free, user-friendly and really powerful GIS software.

Harbours in the Mediterranean Sea.
Figure 1 – Harbors in the Mediterranean Sea (shapefile – vectorial).

To construct the maritime routes, we created CSV files containing each harbor visited by cargoes (so 7 CSV files where created), based on information provided by the website These CSV files were downloaded into QGIS and converted into shapefiles. These shapefiles can be used to draw automatically the roads, using the QGIS plugin “pointsToPaths”. The functionalities of this plugin can be seen in Figure 2.

Figure 2 – Explications about the QGIS plugin “pointsToPaths”

This tool is not perfect because it does not take into account the coastlines. It is then possible that one part of a maritime route passes through the land, which is not desired. To rectify these anomalies, a “by-hand” correction was chosen because they are not many. QGIS allows the user to correct, erase or draw features in a vectorial layer. In order to perform good corrections, it is necessary to preserve the integrity of the vectorial layer, i.e. maintain proper topology (for more information about the topology in GIS, click here). A lot of tools are available on QGIS for the edition of shapefiles. On Figure 3, the 7 digitized routes with the harbors are depicted. The background map is an “open street map” view of the Mediterranean coasts.

Figure 3 – Map of the Incanti maritime routes
  • Gathering data about auctions: crowdsourcing.

The success of the proposed methodology was conditioned by the ability to digitize the numerous auction’s values for the Incanti Venetian system, referenced in the book [1].  To efficiently construct the database, we decided to set up a crowdsourcing initiative. This crowdsourcing involved 10 people, subset of the larger group of 15 people that we initially surveyed. Among the 5 people that did not participate to the crowdsourcing,  one refused the task and 4 did not provide any answer to our proposal. Goodies were promised to the participants as an incentive to take part to the experiment (swiss chocolate).
Each participant received a “pdf” scan of one table of data and had to transcript it in an Excel sheet. To guide them in their task and ensure an homogeneous format for the transcripted data, we wrote a procedure with examples and recommendations on the way to proceed in case of an ambiguous data.

Once we received the Excel sheets from the participants, we merged them in a single database, and cleaned the data from any left ambiguity. To facilitate the analysis of the results, we converted all the auction’s values to a single currency, the italian lire. The rates for the different currencies and the lire are given in the following table (sources: [3] and [4]):

Currency Conversion in lire
Soldi 0.05
Denarii 0.004
Ducats 2.4

Results – Historical interpretation 

The variations of the auctions observed through the whole period of interest are more due to the allure of the businessmen than the simple economic conditions in Mediterranean Sea. The historical analysis will be done on this point of view, for five periods highlighted by Doris Stöckly:

  • Period 1: 1332-1350
  • Period 2: 1355-1377
  • Period 3: 1382-1402
  • Period 4: 1403-1430
  • Period 5: 1431-1453

The animation (changing every ~5 seconds) below provides a visual representation of the auction’s values for the seven Incanti maritime routes. It represents five map of the Mediterranean Sea with the seven maritime routes. Each map depicts the Incanti situation for one of the five periods defined before. The thickness of the lines representing the maritime routes is linearly proportional to the sum of the auction’s values for one route, over one period. This was done using the “buffer” tool included in the GIS software “QGIS”: “a buffer polygon represents the area within a specified distance of an object [the maritime routes]” [5].

Animation of the auctions throughout the five periods – See all the maps individually here.

Period 1: 1332-1350. The Incanti system was born in 1332, under the leadership of the Venetian senate. The Romania’s route was the more used one because of the impossibility of business relationships with the Middle East at the beginning of this period. The traditional relationship between Venice and Constantinople is an historical fact because it exists from the fourth crusade. During the whole era of the Incanti, the Republic of Venice took special care to maintain good and durable relationships with Constantinople and the Black Sea. For Venice, it was a really important and symbolical relationship.

From 1344, the relationships began with the Middle East (Beirut and Armenia) and the importance of Cyprus in the Mediterranean business rose. Moreover, first galleys were sent to Alexandria through a new maritime route, when the pope enables again the relationships with Alexandria. The relationships with the Flanders began also slowly at this time.

The Cyprus/Armenia line is also one of the oldest route. It was really important for the Mediterranean trade. Indeed, the Armenia had a strategically geographical position at the end of the principal terrestrial routes that connected the Asia with the Europe. With the opening of the Alexandria’s line (after the decision of the pope) in 1344, the Armenia’s line was less used because the Alexandria’s line offered a more direct connection between Venice and the African precious metals, peppers and spices.

The Flanders’ route is the logical prolongation of the business relationships in the whole Mediterranean basin. In fact, Venice sent a lot of different goods in the North of Europe like wood, spices, alum or silk.

Interruption: 5 years (1350-1355), due to the third Venetian-Genoese War.

Period 2: 1355-1377. The Alexandria’s route took the more important place in the Incanti system and it confirms the greater interest of the Venetian people for this route and the increase of the trade with Africa. The Cyprus/Armenia and Romania lines were less used than before the war. The interests of the businessmen have moved to the South East (Egypt) of the Mediterranean Sea. Moreover, the auction’s values for the Flanders’ route increased denoting therefore a great interest for the re-exportation of goods from the Middle East.

Finally, a new line was born: the Beirut’s one. This route was like a support for the Cyprus/Armenia’s route and was the last one to be born in the East of the Mediterranean Sea.

Interruption: 5 years (1377-1382), due to War.

Period 3: 1382-1402. At the recovery of the navigation in 1382, the Alexandria’s line was always to more popular one for the business in Mediterranean Sea: it represents 37% [1, p.186] of the total auction’s values for this period. The line of Cyprus is stopped after the war and then, the Beirut’s route began to transport goods from Cyprus as well. The products of Cyprus were always really appreciated by the Venetian people. This fact explains the relative high importance of the Beirut’s route, for this period. Now, the commercial relationships with the Middle East and the Egypt represent 70% [1, p. 187] of the total Incanti business. Unfortunately, the Romania’s route suffered of this fact and its auction’s value decreased in comparison with the previous periods. This drop can also be explained by the Venetian will to diversify the commercial relationships of the Republic. This fact can also be observed with the Flanders’ line, which took a huge importance from 1382. Venice imported a lot of goods from Africa and Middle East (through the Alexandria and Beirut routes) and needed to send away a part of them; the North was the natural choice. The Aigues-Mortes’s route was also created during this period to diversify the Venetian commercial activities and to re-export the oriental goods to the France and Catalonia.

Period 4: 1403-1430. The interest for the Romania’s route is constant, although the Aigues-Mortes’s route was born. The Beirut and Alexandria routes were really important during this period and testify that the interest of the businessmen for diversified goods from Middle East did not decrease. The Flanders’ route is always really strong (re-exportations to the North). The Aigues-Mortes’s route was a good idea as well!

Period 5: 1431-1453. The regulation of the pepper business increased the interest for the Middle East lines (Alexandria and Beirut). Moreover, the route of Cyprus was reopened but not really used (less than 1% [1,p.188] of the total business of this period). Nevertheless, in total, 58% of the business was done in this part of the Sea. During this period, spices’ prices were really high and the European businessmen began to buy their spices in Constantinople rather than in Alexandria, because they were less expansive in the Black Sea’s region! It can explain the sudden new interest for the oldest route: the Romania’s one (with 20% of the total Incanti [1], one century after its creation!). The Aigues-Mortes’s and Flanders’ routes kept their role (i.e. redistribution of goods), in the Mediterranean basin. Moreover, a new line was created, the Barbaria’s one. This line is created because goods of the Maghreb interested the Venetian senate: gold, animal skins, slaves and tissues. It also permitted to connect different civilisations of the Mediterranean Sea.

Both Figure 4 and the animation illustrate the different facts discussed above.

Figure 4: Evolution of the auction values over 5 historical periods
  • The Alexandria’s line is the most important one from 1344, when the interest of the Middle East goods is growing as the pope authorized the commerce with the Muslims. This interest remains dominant.
  • The Beirut’s line shows the same tendency.
  • The Romania’s line is an important one for the Venetian senate, in an historical point of view. It remains always in operation but suffers a little bit during the period 1355-1430 when Middle East goods were more interesting for European businessmen. It grows again from 1431, when the prices of spices were higher in Alexandria than in Constantinople.
  • The route of Cyprus shows a decreasing tendency because it was slowly replaced by the Beirut’s and Alexandria’s ones.
  • Finally, the Flanders’, Aigues-Mortes’s and Barrbaria’s routes are routes with increasing importance, showing the will of the Venetian senate to redistribute the goods in the whole Mediterranean Sea and to be in the center of this commercial system.

Finally, figure 5 shows the relative importance of each route, weighted with their respective years of operation. We see that the Alexandria’s and Beirut’s routes are the two more valuable maritime routes, i.e. that their auction’s values per year are the biggest ones (~500 lires/year) for 88 and 68 years of operation, respectively. In contrast, the Barbaria’s route was operating only during 16 years but it shows high mean auction’s value per year. This highlights the relative importance of this “young and borderline” route, although it was initially built only to complete the maritime exchanges in the basin. On the other hand, the Romania’s route shows relatively low level of auctions and a really long activity time (102, i.e. all over the Incanti era). This reveals that this route was not the preferred of the businessmen but was probably maintained by the senate because of historical reasons (at least until the increasing of the spices’ prices in Alexandria…). The Cyprus’ route, with 35 years of operation, shows good performances as well. Finally, the two last routes are like “reinforcement” routes, used for re-exportations of goods. The most used is the the Flanders’ route with a mean auction’s value of 340 lires/year, followed by the Aigues-Mortes’s one (186 lires/year).

Figure 5 – Equivalent auction values per year of operation


The Venitian Incanti system permits to develop the business over the Mediterranean Sea, with Venice as principal hub. A huge part of the importations came from the Middle East and the Egypt. Venice had permanent commercial relationships with the Black Sea as well. Finally, they successfully developed a complete system of re-exportations of goods in order to distribute Middle East products to the North and the West of the Mediterranean Sea. The maps offer a good representation of the evolution of the different maritime routes and allow the reader to instantly understand this complexe commercial system.


[1] Doris Stöckly, Le système de l’Incanto des galées du marché à Venise (fin du XIIIe – milieu du XVe siècle), Université de Paris, 1992.

[2] Web-SIG of the EPFL Digital Humanities Lab,

[3], consulted 01/04/2015

[4], consulted 01/04/2015

[5] C. D. Lloyd, “Spatial Data Analysis, an introduction for GIS users”, Oxford University press, New York, 2010, p. 47.