The career of the Hegelian theologian Bruno Bauer is marked by his radical and sudden turn from a defender of Christianity into one of its most extreme critics, from a champion of orthodox Christianity into what one of his admirers called a "Robespierre of Theology." Although his many theological and historical writings are largely unread today, his ideas influenced his own age and have found reflection in the works of such twentieth-century thinkers as the theologian Hans Küng and the philosopher Jürgen Habermas.

Bauer was born on 6 September 1809 in Eisenberg, Martin Luther's birthplace, to Friedrich Wilhelm Bauer, a porcelain painter, and Caroline Wilhelmine Bauer, née Reichardt. He was the oldest of four brothers; the others were Egbert, born in 1811; Egino, born in 1813; and Edgar, born in 1820. In 1815, Friedrich moved his family to Berlin, where he entered into secure employment at the royal...