The endeavours to develop an artificial stone which is freely-formable in the unset state go back far in history. The initial application of malleable mineral compounds was presumably intended to enhance the adhesion between, and to equalise dimensional imperfections of, layered natural stones or bricks. In the later development, already in late antiquity, however, the entire regular masonry bond was replaced by a mixture of aggregate and artificial petrified mass, so that stones, as a rule, were only randomly embedded within the concrete. Thus, the entire building structure was cast from one single piece, similar as with modern concrete.