These models are part of a revival deliberately fostered by the 26th Dynasty, who rose to power in Sais in 663 B.C.  Egypt had endured a long period of decline, civil war & invasion.  The Saite rulers understood the propaganda value of temple art, validating the pharaoh's claim of being himself a god.  Thus after an interval of over 4 centuries, a new beginning was necessary.  These artists drew their inspiration chiefly from the Old Kingdom and had copies made of reliefs and statues for the guidance of the apprentices in the royal studios.  The result of these activities was the formulation of an official style of art.  The models discussed demonstrate this.  They were prepared at a central point & distributed wherever new temples were erected.  The sculptors of the Saite revival survived the fall of the dynasty (525 B.C), survived 2 centuries of Persian rule & when the Ptolemys took over, they were quick to adopt the same style of art, as formulated by the sculptors of the 26 Dynasty.  That the Saite style should have lasted for 6 centuries without essential change is astonishing.  These are the same centuries which saw the rise of Greek sculpture, its flowering & extinction and during the last half of this period Alexandria was the principal Hellenistic world centre of culture.  Yet Greek ideas in art or religion left no impress on Egypt even in the declining years of her long Winter.