International audiencePurple in Roman Egypt: Recent Discoveries, Technical, Economical and Social ImplicationsWe present the results of dye analyses of archaeological textiles from the three first centuries CE,discovered in the rubbish dumps of Didymoi, a military site in the Eastern Desert of Egypt: true purplefrom marine molluscs has been identified in ten fragments. These results are discussed from the pointof view of the possible biological sources, production centres and technical processes that might beinvolved. Calculations of the quantities of purple-dyed wool necessary to decorate the types of garmentsfrom which the fragments originally came from, are then presented. Such calculations permit estimationsof the extra cost induced by ...