2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33577I sketch the main lines of development of the research in quantum gravity, from the first explorations in the early thirties to nowadays.Presented at the 9th Marcel Grossmann Meeting in Roma, July 2000. New revision, on the basis of numerous new inputs. Many thanks to everybody who wroteGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext