This chapter is dedicated to the Wilhelmine Empire (Kaiserreich), an era that saw the apex of German imperial expansionism. It was a period ripe with numerous intersecting visions of supersessionism, expansion, and domination. A major challenge for Baeck was Adolf Harnack’s turn-of-the-century popular lectures and subsequent book titled The Essence of Christianity. Harnack presented a pure and positive essence of Christianity against a legalistic and negative Jewish tradition. Baeck’s first major work, The Essence of Judaism (1905) responds to Harnack and subsequent challenges from the History of Religions School. Yet this type of response was shaped by the heydays of German imperialism, both abroad and in the attempts to colonize the former Polish territories. This is a formative phase for Baeck’s thought and many of his ideas, including the distinction between state power (Macht) and spiritual energy (Kraft), his views on Jewish missionizing, as well as his relation to Zionism. All these emerge in this period and continue to play a role in his thought throughout his life.