Probably no leader in antiquity captured the relationship between ideology and foreign policy more eloquently than Pericles in the funeral oration he delivered at the burial of the first Athenian soldiers killed in the war between Athens and Sparta. According to Pericles, the Athenian soldiers who died perished to defend a political ideal, a democratic way of life. My interest, however, is not motivated by the desire to locate the period when a set of political leaders first used ideology as a foreign policy instrument. As already noted, one of my intellectual aims is to bring to light the sources of the ideological structures that define, and contradictions that affect, today’s world system. My objectives in this chapter are to explain: i) the transformation of religion into political ideology; ii) the way leaders first used religious-based ideologies either to help prevent the demise of an empire or create a new one; and iii) how a political ideology helped prevent the leaders of an empire from expanding its power far beyond their regional base.