Fortifications of the city of Trogir: Visualising changes from 220BCE until 1900CE

Team Members Participating:

Ana Plosnić Škarić – PI
PhD in Art History from the U of Zagreb, Croatia
Institute of Art History, Croatia

Ana Šverko – Team Member
PhD in Architectural History from the U of Zagreb, Croatia
Institute of Art History, Croatia

Project Summary:
The project “Fortifications of the city of Trogir: Visualising changes from 220BCE until 1900CE” is conducted at the Institute of Art History, Croatia.
Due to the preservation of its urban and architectural fabric, the city of Trogir is listed on UNESCO’s World Heritage List ( ). As such it represents an excellent model for urban change studies.
The aim of the project is the further and in-depth research of the changes to the fortifications of the city of Trogir as well as the presentation of relevant data in the form of analytical maps (GIS) and the presentation of research results in the form of 3D models.
The first known city walls of Trogir are from the Hellenistic period. As the city grew new walls or a new part of the walls were erected during the Late Antique, Early Medieval and High Medieval periods. From the 15th century onwards, the development of artillery weapons hastened their modernisation, which resulted in the construction of the bastions. These fortifications protected the city until the beginning of the 19th century, when they began to be dismantled to enable further development of the city. However, a large part of the medieval city walls is still preserved. Archaeological research improves our knowledge of the development of the fortifications before the High Medieval period. Apart from studying these physical remains, our research will encompass written data: archival documents and historiographic texts. Furthermore, it will include a critical analysis of historical maps and images of the city. Valuable sources for this project are recently-discovered architectural drawings of the fortifications, produced around 1800 for the Venetian Garagnin family, who had moved to Trogir at the end of the 16th century. The Garagnins engaged the famous Italian architects Giannantonio Selva from Venice and Basilio Mazzoli from Rome to design architectural projects for family properties located beside the city walls. Documents connected to their projects that depict portions of the city walls, as well as a number of city maps from the 19th century, represent the core of the research project. They are to be analysed within the wide contexts of state-of-art and the existing knowledge of the changes to Trogir’s fortifications.
The project’s goal is to offer digital representations of the changes to the fortifications over a long time period. Due to the varied nature of the preserved data, the work is divided into two major parts: the first from 220BCE until 1500 (APS), and the second from 1500 onwards (AS). For the same reason, different methodologies will be applied.
The data on the fortifications until 1500 are all preserved in fragments. They encompass parts of the city walls preserved in their full height and those preserved on the ground level. Archaeological excavations have revealed those parts preserved under what is today the street level, or foundations. Historical maps, plans, images and photographs include data about the fortifications that are not preserved. Additional data come from textual sources, including local historiography (from the mid-17th century) and notarial documents and judicial acts (from 1263 until 1500). The challenge is to structure all these data into a GIS database that will subsequently be used for exporting analytical 2D maps. These analytical maps will clearly reveal all the preserved data and as such will be scholarly output that supports the schematic 3D models reflecting the changes to the fortifications. These 3D models are meant to facilitate the understanding of all interested members of the public.
Given the varied nature of the materials available for reconstructing the historical changes to the Trogir city walls, studying their transformation in the period from 1500 to 1900 is based on a different methodology to that used to research earlier periods. The majority of the materials are precise archival blueprints and photodocumentation from Croatian, Italian and Austrian archives, and documentation showing the current state of the fortifications. Along with supporting materials – detailed written historical, land registry and land survey records – it is possible to very precisely reconstruct the condition of the walls, particularly around the year 1800. It is thanks to the rich written and visual records that the documentation from this period served as a starting-point for the creation of the original 3D model of the Trogir fortifications in AutoCAD. To complete this model, it will be adapted to the data from the chosen periods with a shift in time towards 1500 on one side, and 1900 on the other, which reflect the key phases of change. Each phase is accompanied by a list of sources that were used for the reconstruction. The aim is to further photogrammetrically process the final phase in selected parts. The final goal is to join together all these visual representations of the historical changes to Trogir’s walls in an animation that in fact unites the otherwise broad range of archival materials, creating a model that allows us to communicate more directly with the past, and opening up new possibilities for research.
This research necessarily includes collaboration with, and investigation of, the holdings of the Municipal Museum of Trogir, the State Archive of Split, the State Archive of Zadar, the Kriegsarchive in Vienna.
Both team members, as PI-s, have successfully conducted 3-year projects, using outsourcing for web programming: APS: Dubrovnik: Civitas et Acta Consiliorum. Visualizing Development of the Late Medieval Urban Fabric ( ), AS: Grand Tour Dalmatia – Dalmatia – a destination of the European Grand Tour in the 18th and the 19th century ( ).

External Link(s):

The project is a part of a long-term urban history research that has been conducted at the Institute of Art History, Croatia, since the time it was founded (1961) (see:; and, especially the chapter: ; information about other publications and the projects are also available at the IPU web pages).
Presentation Slides (PDF)