Signs
In the Middle Ages and early modern period sigillum or signum were the terms used to refer to seals. Every seal was a sign with which a seal bearer certified or legitimated something else, be it a document or a relic, by the impression of the seal matrix in wax. This basic function also frequently brought about a seal image that was emblematic, usually manifesting the characteristics of two-dimensional design, geometrical composition and the simplified representation of objects, all of which refer to the owner of the seal and the specific function of the seal itself. The seal of the bishopric of Fiesole, by way of example, bears the concentric circles of celestial spheres, the arm and the blessing hand of St. Peter with the keys and the half moon as the emblem of Fiesole. The seal matrix of a judge, on the other hand, displays, with a minimum number of strokes, a boat with five oars, while the cobblers’ seal portrays the contour of the sole a shoe. Finally, the seal impression of the hospital order of the Holy Spirit in Rome shows the double cross with the Heads of the Apostles as a precisely and geometrically ordered framing motif, whose features are, nevertheless, individually represented.
