Summary: The institution of the Ombudsman was formally established for the first time in Sweden in 1809. The main idea behind the establishment of this institution was to control the activities of the state administration and to recognise the complaints of people affected by the illegal and harmful activities of state bodies. However, the idea to establish this institution was not new, because in the history of Swedish law, this institution has already had its achievements. It was not until 1809 that such an Ombudsman was elected for the first time in the Swedish Parliament, by secret ballot, as an independent body. Until 1917, the Kingdom of Sweden was the only country in the world to have the institution of the Ombudsman. Also in the same year Finland, having gained independence from Russia, established the Ombudsman‘s Office according to Swedish solutions. Then, in the 1950s, the Kingdom of Denmark was the next country to establish the Ombudsman‘s body. Following the development of the Ombudsman‘s institution in the Scandinavian countries and the subsequent process of democratisation of social life, the Ombudsman institution was established in 1987 in Poland. Today, even within the European Union, the European Ombudsman functions as an institution for the extra-judicial control of the activities of the bodies and agencies of the European Union. The function of bodies such as the European Ombudsman is to ensure that citizens‘ rights are actually respected. The European Ombudsman strengthens the rule of law in the European Union and complements the role of the courts by providing opportunities for low-cost, accessible individual redress and, on the other hand, complements the representative function of the European Parliament by becoming a centre for independent critical assessment and improvement of the quality of the European administration. The rule of law serves to maintain the EU system as a supranational system. It is the construction of the integration axis. When there is a lack of trust in the community in this respect, it begins to be treated differently. It is therefore important that the European Ombudsman fulfils his Treaty obligations effectively.