Due to the extensive reforms of the Prussian administration, Prussia was structurally modernized between 1806 and 1815. Afterwards, ‘experts’ dominated the new political decision-making system. Nevertheless, the (self-) conception of the monarch as the last resort conflicted with the professional conception of the new epistemic group of ‘experts’ in charge. By examining the Chaussee sector in Prussia, the chapter shows that while the monarchic will on its own did not suffice to legitimate political decisions after the onset of early modernization, the authority of the monarch still enabled him to veto and initiate policies. The final formation of a specific horizon of interpretation was only realized when the king withdrew as a decision-relevant actor in the 1830s/1840s.