Let W be a compact hyperbolic n-manifold with totally geodesic boundary. We prove that if n > 3 then the holonomy representation of π 1 (W ) into the isometry group of hyperbolic n-space is infinitesimally rigid.Starting with a complete hyperbolic manifold X, when is it possible to deform its hyperbolic structure? If X is a finite area surface, its metric always has nontrivial deformations through complete hyperbolic metrics. However, in all higher dimensions, the work of Calabi, Weil, and Garland combine to prove that there are no nontrivial deformations through complete metrics when X has finite volume [3,25,6]. In search of flexibility, one is led to study infinite volume hyperbolic manifolds.In dimension 3 infinite volume hyperbolic manifolds have been studied for many years. A particularly well-understood class of such manifolds are the convex cocompact ones. They are topologically the interior of a compact 3-manifold with boundary consisting of surfaces of genus at least 2. Convex cocompact hyperbolic 3-manifolds have large deformation spaces parametrized by conformal structures on their boundary surfaces inherited from the sphere at infinity. In higher dimensions the situation becomes more mysterious, but one expects to find less flexibility than in dimension 3. This article's research began by looking for a large class of infinite volume hyperbolic manifolds, present in all dimensions, and rigid in dimensions greater than 3. In high dimensions it is difficult to construct interesting infinite volume hyperbolic manifolds. One method is to begin with a closed hyperbolic manifold (often constructed by arithmetic tools) that contains an embedded totally geodesic hypersurface and cut along the hypersurface to obtain a compact hyperbolic manifold W n with totally geodesic boundary. There is a canonical extension of such a structure to a complete, infinite volume hyperbolic metric on an open manifold X n without boundary which is diffeomorphic to the interior of W n . This is the class of manifolds we will study.Associated to any hyperbolic manifold is a representation, called the holonomy representation, of its fundamental group in the group Isom(H n ) of isometries of n-dimensional hyperbolic space. When it is a compact hyperbolic manifold W with totally geodesic boundary, the representation is discrete and faithful. If we denote Date: October 27, 2018.