This paper describes the vision of the More Electric Aero Engine; in particular, identifying the areas in which a change of technology can be introduced and the benefits to be gained from its implementation. The paper goes on to describe the design challenges being faced by Rolls-Royce and the Power Optimised Aircraft consortium partners in integrating the prototype technologies on the demonstrator engine. The paper concludes with a review of the key areas for future research, which are required to fully exploit the benefits of electrical technologies in this physically demanding environment.