Building Shalfak Project overview Shalfak is one of two surviving Middle Kingdom fortresses in Lower Nubia. It is situated 330 km behind the Aswan Dam, 50 km south of the Egyptian‐Sudanese border on an island in Lake Nubia. Shalfak was built under Senusret III as one in a chain of 17 fortresses which the rulers of the 12th Dynasty constructed to secure Egypt's southern border against the Kingdom of Kerma. The isolated position and the arid climate have contributed to the excellent preservation of Shalfak's architectural substance. Its mudbrick walls still stand up to 8.3 metres high. Organic building materials survive in an unparalleled condition. They include both timber in a variety of uses and matting, which was inserted into the mudbrick walls at regular intervals. While previous research into the Nubian fortresses centred on functional aspects of their military and administrative installations, limited attention was given to building techniques, the supply and employment of resources and the question of how these massive monuments would have been maintained. The Building Shalfak project taps into the unique potential of the site to study these aspects and explore how state-level building enterprises were organised and conducted at the heyday of the Middle Kingdom. As part of the Shalfak Archaeological Mission (SAM), the project is directed by Dr Claudia Näser of University College London. Season 2017 The first field season started with a detailed mapping of the monument. The plan which was generated from the over 2800 measuring points now forms the basis for the architectural analysis and the wider condition mapping. The project's architect Peter Becker inspecting layers of cross beams at the inner face of the fortification wall (South Wall) As archaeological material can be exported from Sudan, a first series of samples of the organic building materials was obtained. They were identified as acacia (Acacia sp.) and a Halfa grass (Desmostachya bipinnata). Environmental reconstructions indicate that both species were locally available in antiquity – which represents a first step towards identifying chains of procurement, distribution and employment of resources. Beam with square section and trimming marks from an adze in situ in a niche in the outer fortification wall (outer face of North Wing Wall) Halfa grass mat with remains of binding, in situ in the fortification wall (East Wall) First analyses suggest that acacia logs and Halfa grass mats were inserted in the wall bodies to counter shrinkage effects, much in the same way as steel reinforcements in present-day concrete constructions. The use of cross beams and matting in mudbrick walls was not developed in the Nubian fortresses, but has been noted in monuments in Egypt from the Old Kingdom onwards. The study of the evidence from Shalfak thus helps to understand technological aspects of mudbrick architecture in a much wider chronological trajectory. Outer face of the fortification wall with preserved wall paint (North Wing Wall) Another discovery sheds light on the visual appearance of the Middle Kingdom military architecture. During the mapping survey, remains of colour were noted – indicating that the outer fortification walls were painted in yellow on a white background. The discovery of a workplace, complete with lumps of pigment and a tool sherd preserving copious amounts of yellow and white paint, further substantiates this finding. The pigments currently undergo scientific analysis. Tool sherd with yellow and white pigment from the workplace in front of the painted wall (see previous image) Upcoming season 2018 In the upcoming 2018 season, the architectural survey shall be continued to explore details of Shalfak's building history and to systematise observations on the use of building techniques and materials. In the first season, excavations had focussed on an extra-mural workshop area and the administrative part of the granary building. They shall now be extended to the actual storage part of the granary. Results are eagerly awaited for a range of research questions. With regard to the Building Shalfak project, they will provide data about the differential use of building techniques and materials in diverse functional contexts. Further reading Näser, C., Becker, P., Kossatz, K., Khaleel Elawad Karrar, O. 2017. 'Shalfak Archaeological Mission (SAM): The 2017 field season', Journal of Egyptian Archaeology 103.1. Näser, C. 2018. 'A Middle Kingdom fortress in the Middle of Lake Nubia', Egyptian Archaeology, forthcoming.