Diverse roles for black holes in string theory

String theory is a theory of gravity and should therefore contain black holes. In fact, it contains a richer spectrum of solitons, known collectively as the black p-branes. Some of what string theory implies for p-branes, and what p-branes imply for string theory, is examined. To start, properties of the 11-dimensional membrane and five-brane are elucidated from the general relativistic approximation.; Type IIB strings are compactified on a Calabi-Yau three-fold with Calabi-Yau valued expectation values given to the three-form field strengths. This leads to non-zero charges for the dilaton hypermultiplet. The classical potential for the dilaton multiplet is computed. It is found that supersymmetry is completely broken, except at special points in the moduli space where massless black holes appear.; The moduli space metric describing the scattering of four and five dimensional black holes is computed using the method due to Manton, as adapted to black hole physics by Ferrell and Eardley.; By taking the near-horizon limit of these black holes, some properties of low-dimensional anti-de Sitter spaces are obtained. In particular, the fragmentation of two-dimensional anti-de Sitter space is discussed. Some comments are also made about higher dimensional anti-de Sitter fragmentation.