This paper presents a relativistic generalization of Milgrom's Modified Newtonian Dynamics (MOND) paradigm, known as TeVeS (Tensor-Vector-Scalar theory). TeVeS is a relativistic gravitational theory that incorporates MOND's nonrelativistic limit while also being consistent with general relativity (GR) in the strong acceleration regime. The theory is based on three dynamical fields: an Einstein metric, a timelike 4-vector field, and a scalar field. It also includes a non-dynamical scalar field, which is used to define the physical metric in terms of the Einstein metric and the 4-vector field. TeVeS is constructed to satisfy several key principles, including an action principle, relativistic invariance, the equivalence principle, causality, and the requirement for a preferred scale of acceleration below which departures from Newtonian gravity occur. The theory is shown to pass the usual solar system tests of GR, predicts gravitational lensing in agreement with observations without requiring dark matter, and does not exhibit superluminal propagation. It also provides a formalism for constructing cosmological models. The paper reviews previous attempts to develop relativistic MOND theories, including relativistic AQUAL, Phase Coupled Gravity (PCG), and disformal metric theories. These theories face challenges such as superluminal propagation and insufficient light deflection. TeVeS addresses these issues by incorporating a scalar field and a 4-vector field, which allows for a consistent relativistic formulation of MOND. The theory is shown to have a Newtonian limit for nonrelativistic dynamics with significant acceleration and a MOND limit for small accelerations. It also agrees with the solar system's post-Newtonian tests and predicts gravitational lensing in agreement with observations. The scalar field in TeVeS evolves slowly, making it suitable for cosmological models. The theory is shown to be consistent with the observed Tully-Fisher law and other MOND successes, and it provides a framework for understanding extragalactic dynamics without invoking dark matter.This paper presents a relativistic generalization of Milgrom's Modified Newtonian Dynamics (MOND) paradigm, known as TeVeS (Tensor-Vector-Scalar theory). TeVeS is a relativistic gravitational theory that incorporates MOND's nonrelativistic limit while also being consistent with general relativity (GR) in the strong acceleration regime. The theory is based on three dynamical fields: an Einstein metric, a timelike 4-vector field, and a scalar field. It also includes a non-dynamical scalar field, which is used to define the physical metric in terms of the Einstein metric and the 4-vector field. TeVeS is constructed to satisfy several key principles, including an action principle, relativistic invariance, the equivalence principle, causality, and the requirement for a preferred scale of acceleration below which departures from Newtonian gravity occur. The theory is shown to pass the usual solar system tests of GR, predicts gravitational lensing in agreement with observations without requiring dark matter, and does not exhibit superluminal propagation. It also provides a formalism for constructing cosmological models. The paper reviews previous attempts to develop relativistic MOND theories, including relativistic AQUAL, Phase Coupled Gravity (PCG), and disformal metric theories. These theories face challenges such as superluminal propagation and insufficient light deflection. TeVeS addresses these issues by incorporating a scalar field and a 4-vector field, which allows for a consistent relativistic formulation of MOND. The theory is shown to have a Newtonian limit for nonrelativistic dynamics with significant acceleration and a MOND limit for small accelerations. It also agrees with the solar system's post-Newtonian tests and predicts gravitational lensing in agreement with observations. The scalar field in TeVeS evolves slowly, making it suitable for cosmological models. The theory is shown to be consistent with the observed Tully-Fisher law and other MOND successes, and it provides a framework for understanding extragalactic dynamics without invoking dark matter.