According to Meurer the source for this map is Daniel Speckel's three-sheet map of Elsas. Speckel (1536-89) is identified on the map as the source. He was a native of Strasbourg and an engraver by profession. He was also a fortress engineer and architect. He travelled extensively building various fortresses in Hungary, Vienna and The Netherlands. Abraham Ortelius here employs him to produce a map of the region around Strasbourg for the 'Theatrum Orbis Terrarum' which was first issued in 1584. Van den Broecke, M. 112b; Karrow 1/132; Meurer pp. 243-4; Norton 'Daniel Speklin: map-maker and architect', in 'Mapline' 21 pp. 1-2.