The Constitution of 1818 was to be understood as a gift of the king (Oktroy) and thus an emanation of royal sovereignty. The king had considerable importance in both the legislative and executive branches: laws were only effective with his signature, he appointed and dismissed the ministers, was commander-in-chief of the army and headed the state council. The ministerial indictment was the only way for the state parliament to take action against the government (ministers and deputies) in the event of unconstitutionality. Moreover, the king had jurisdiction. In the end, therefore, the power of the state lay with the monarch alone. At the same time, however, he took an oath on the constitution: an expression of voluntary self-restraint as a concession to comply with the constitution.

In the constitution the monarchical principle was particularly expressed in Title II § 1: “Der König ist das Oberhaupt des Staates, vereiniget in sich alle Rechte der Staatsgewalt, und übt sie unter den von Ihm gegebenen in der gegenwärtigen Verfassungs-Urkunde festgesetzten Bestimmungen aus. Seine Person ist heilig und unverletzlich” (The King is the Head of State, uniting in himself all the rights of the authority of the State, and exercising them under the provisions laid down by him in the present constitutional document. His person is holy and inviolable). The king thus became the figurehead of the new kingdom. The monarchical principle as the basis of constitutional monarchy stood in contrast to popular representation, which constituted the main component of royal restraint of state authority. From the beginning, a dichotomy between these two institutions became increasingly apparent.

A profound change in the role of the monarch took place under Ludwig II (1845–1886, king from 1864), who increasingly retired from governmental duties, while the influence of his advisers and ministers became stronger. With his deposition on 9 June 1886 and the transfer of the regency to Prince Regent Luitpold (1821–1921, regent 1886–1912) the so-called “Prinzregenten” period began, which is seen as a phase of reform and change on the one side and as a period of crisis and decay of the constitutional state on the other.

After Luitpold’s death, his son Ludwig (1845–1921, regent 1912–1913, king 1913–1918) took over the regency. In 1913, by means of a constitutional change, Ludwig replaced the invalid Otto (1848–1916, king 1886–1913) and was enthroned as monarch.