This chapter will offer an introductory sketch of the theory and practice of the multinational firm. Of necessity it will be a still image of a moving, elusive phenomenon. The sketch will be drawn, moreover, from a moral angle; it highlights the vast powers of multinationals, the existing codes and laws influencing their activities, and the rare theoretical attempts that have been made to understand their ethical responsibilities. Yet it attempts almost no moral analysis. Its aim is descriptive; it is to serve as a preliminary for the moral analysis that will follow.