The common structure to all models of fundamental forces of nature among constituent particles of matter are gauge field theories with Higgs mechanism implemented for mass generation. Mathematically speaking, these are nothing but theories of connection and curvature on principal fiber bundles over space-time. After a short overview of the Standard Theory of Weak and Strong Interactions, we concentrate on gauge theoretic aspects of gravitational forces. In particular Einstein’s theory of general relativity will be given as a gauge theory of the local Lorentz group.