The Kulturkampf was the effort by the Prussian prime minister, Otto von Bismarck (a Protestant), to expel the Catholic Church from Germany in his endeavor to unite the Germans into an empire in the late nineteenth century.
Bismarck was opposed in his efforts by the Center Party, a group formed to support the Catholics in 1870. They had originally been supporting Bismarck’s endeavors, but withdrew their support once he decided to expel the Catholic Church.
In his efforts to expel the Catholics Bismarck expelled the Jesuits, Dominicans and Franciscans, took the priests off of the payroll and eliminated Catholic Church supervision over German education. Finally, in 1873, he passed the May Laws, which passed the training of the clergy over from the Church to the government.
However, the real reason for Bismarck’s enmity of the Catholics was his dislike of the Pope, Pius IX. So, when Pius IX died Bismarck ended his endeavors to expel the Catholics and made peace with them, thus ending the Kulturkampf.