This project aims at investigating some crucial issues in globally supersymmetric and Supergravity theories. Firstly, it focuses on perturbative and non-perturbative sources of Supersymmetry Breaking in the low-energy effective Supergravity description of Superstrings and M-theory. These include Gaugings and Fluxes in compactifications from higher dimensions, Gaugino Condensation and other non-perturbative effects generated by (unoriented) D-brane instantons. Secondly, it explores the physics of extremal Black Holes by means of the Attractor Mechanism, that relates their Entropy to the extrema of an Effective Potential. The tantalizing analogy with moduli stabilization in flux compactifications is considered in detail. Moreover, the deep connection between the Entropy-Formula and certain topological string partition functions is exploited to improve the connection between macroscopic and microscopic interpretations. The holographic (AdS/CFT) correspondence conjectured by Maldacena between (super)conformal Yang-Mills theories and certain (super)gravity theories in Anti De Sitter spaces is analyzed in view of the attractive nature of universal horizon geometries and in relation to Higher-Spin Symmetries, that may be associated with bulk duals of certain gauge-invariant composite operators on the boundary. The project also addresses the possible link between higher-spin theories and an unbroken phase of Superstring or M-theory. The project will be carried out through the abilities and the skills of the PI and of the team members, with their complementary expertise on different but interrelated topics in the holographic approach to modern theories of quantum gravity. Supersymmetry and gauge principles will serve as basic tools for their research.