The transition from the Irish Free State to the Republic of Ireland was formalized on December 29, 1937, with the introduction of a new constitution that redefined the country’s political landscape. This change was essential for establishing a national identity independent of British rule. The architect of this new governance structure was Eamon de Valera, who was a dominant political figure and prime mover in the drive for full sovereignty. The constitution replaced the Government of Ireland Act of 1920, which had previously delineated powers between the British crown and Irish governance. The new constitution declared Ireland a sovereign state and sought to reinforce its constitutional legitimacy both domestically and internationally.

The new document introduced various provisions that ensured the protection of individual rights, emphasized the importance of family, and showcased Ireland’s Catholic ethos. It replaced references to the British monarchy, rebranding the state as ‘Ireland’ instead of the previous name, ‘Irish Free State’. This renaming was not merely a change in nomenclature; it was emblematic of a broader sense of national pride and independence. The adoption of the constitution was celebrated within Ireland as a moment of self-determination. Furthermore, it constituted a legal framework that facilitated the process of building and entrenching national institutions, aligning closely with the values and aspirations of the Irish people.

The enactment of the constitution faced opposition from some groups, who felt it was not sufficiently reformist or might further alienate Northern Ireland. However, proponents argued it laid the groundwork for a future wherein Irish governance could be wholly Irish in conception and execution. Changes from the constitution set the stage for modern legislative and political structures in Ireland by articulating the principles of democracy and social justice, which would resonate in the subsequent development of the state, particularly during the mid-to-late 20th century.