Before revision: Illustration by Adolph Menzel, 1846 Austria and Prussia were the most powerful principalities in the Holy Roman Empire by the 18th and 19th centuries and had engaged in a struggle for supremacy in Central Europe .
After revision: Illustration by Adolph Menzel, 1846 Austria and Prussia were the most powerful principalities in the Holy Roman Empire by the 18th and 19th centuries and had engaged in a struggle for supremacy in Germany .