This thesis presents techniques developed for the robust reactive control of autonomous mobile robots navigating in complex environments. Traditional approaches have adopted a top-down perspective by focusing on the reasoning part of path-planning. In contrast, this thesis tackles planning from a bottom-up perspective which is characterised by a tight coupling between perception and action. With this view in mind, control systems ranging from pure reactive controllers to controllers that can construct spatial representations of the environment are investigated. Hand-designed techniques as well as evolutionary approaches are developed and analysed. Quantitative simulation experiments measuring the performance of each control system are presented along with a new algorithm for developing topological maps of the environment from laser range-finder sensory information.