The register of the main events that occurred during the life of a person –the birth, the marriage and the death- in the Ancien Regime was fully monopolized by the Catholic Church. The documents generated, therefore, were preserved in the sacramental register books of the different parishes of the church. The birth of the liberal state brought along the necessity to create a secular register of the aforementioned events. In this context, the Civil Register was introduced in the city of Barcelona by the initiative of its City Council between 1836 and 1842, although the obligatory nature of these registrations were set by the Civil Register Law in 1870. The City Council maintained the competency of the Civil Register, so the register books between 1836 and 1880 are preserved in the Municipal Contemporary Archive of Barcelona. From 1881 onwards, the competency has been exercised directly by the State administration, and the register books generated during this period are preserved in the current building of the institution of the Civil Register of Barcelona.