2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/56176This is a review of some basic features on the relation between supergravity and pure gauge theories with special emphasis on the relation between T-duality and supersymmetry. Some new results concerning the interplay between T-duality and near horizon geometries are presented35 pages, 14 figures, lectures at the Schladming Winter School 1999, Corrected some typosHigh Energy Physics - Theorytext