This paper presents the historical background of the 20th-century technology of geopolymers in light of a literature research of the 15th to 19th centuries and offers a hypothesis on why this historical knowledge was forgotten when Portland cement appeared. The recapitulation of the different cementitious calcareous matters returns all the way to the Bible builders; Ancient Vitruvius Pollio’s work "Ten Books of Architecture". These books were not only read but practically proven in pre-Portland times and especially at the beginning of 19th century. The long-term stability of Roman mortars and constructions was studied from the perspective of the cementitious materials, and the cited literature demonstrates the historical evolution of calcareous cements, then the reasons for the interruption of progress and return to the historical experience in the 1980s., Tomáš Hanzlíček, Ivana Perná, Zdenek Ertl and Sean M. Miller., and Obsahuje bibliografii