Throughout history, reference to the historical constitution of Hungary, which was the uncodified constitution of the state for a thousand years, was used to achieve different and sometimes conflicting goals. Since 2012, the historical constitution has become a constitutional concept after decades of abandonment. It appears in the Fundamental Law of Hungary (2012) and the jurisprudence of the Hungarian Constitutional Court – both link it to the concept of constitutional identity. This paper claims that the narrative of the Hungarian historical constitution as a constitutional concept that has been becoming predominant in legal texts and scholarly works is conducive to illiberalism. It is so because, instead of leaving it in the domain of historical studies, it has been used by political and constitutional actors to oppose liberal values. Two arguments are presented to justify this claim in the following way. First, the contemporary narratives on the two most important constitutive components of the historical constitution, i.e., continuity and rights expansion, are contrasted with legal measures introduced in the second part of the 19th and the first half of the 20th centuries. This comparison supports the view that the contemporary claims on continuity and rights expansion cannot be verified; on the contrary, they imply exclusion and rights restriction. Second, the relevant jurisprudence of the Hungarian Constitutional Court suggests that the finality of introducing the historical constitution into the constitutional text, and their subsequent linking to the concept of constitutional identity, was to secure the traditional Westphalian understanding of ethnic-national sovereignty, mainly against the rule of law, i.e., EU obligations and globalization. Keywords: historical constitution, Hungary, illiberalism, right expansion, constitutional identity