The iron cabinet, sanctuary of the precious archives that tell the story of France

Beneath the gilded moldings of the Hôtel de Soubise in Paris, General de Gaulle's manuscript of the June 18 Appeal, presented to the State by his family, sits the manuscript. From Wednesday, June 18, until September 1, this piece will be on display in a glass case before being placed in the "iron cabinet" of the national archives. Behind the doors of this vault, it will stand alongside some of the most precious documents in the national narrative.

This iron cabinet, created after the French Revolution , was first installed in the Tuileries to store the tools for manufacturing revolutionary currency. It was then used to collect and protect all the acts of the new National Assembly. It then became the official repository for revolutionary constitutions, laws and decrees, before being transferred, in 1808, to the Hôtel de Soubise.

Under the leadership of Jules Michelet, head of the historical section of the National Archives, it was enriched with documents considered seminal. A tradition of preservation that has survived. Today, it contains nearly 1,150 testimonies of French history.

Among the first documents received was the register of sessions and oaths of the Jeu de Paume. These 699 pages record the deputies' solemn promise not to separate until they had agreed on the Constitution. Alongside it is the certified version of the 1791 Constitution, encased between two copper plates to protect it from destruction. The Declaration of the Rights of Man and of the Citizen, engraved on a bronze plate, completes this triptych.

The final moments of absolute monarchy are preserved behind these steel doors. It is possible to read Louis XVI's will, written in the Temple prison. In it, the king pardons his enemies, refutes accusations of treason, and advises his son, should he one day ascend the throne, to renounce all revenge. Beside it, Marie-Antoinette's unfinished letter. Written on the night of October 16, 1793, at the Conciergerie, she entrusts custody of her children to her sister and addresses her last words to the woman who will never read them.

The cabinet also houses evidence of the scientific revolution. Among them is the minutes of the deposit of the prototypes of the meter and the kilogram , dated June 22, 1799. This archival document describes the submission to the National Archives of the platinum prototypes of the meter and the kilogram – the fruit of the work of Borda, Monge and Lavoisier – and officially establishes their characteristics and conservation conditions.

Like its history, the archives hidden there extend beyond the borders of France. The constitutional law of June 25, 1992, which made possible the ratification of the Maastricht Treaty transforming the European Community into a political and economic union, was tabled in 1996.

Further on, the story of French colonization is being written. Like the letter from the Algerian Emir Abd el-Kader in 1852, written in Arabic, in which he sets out the conditions of his surrender and exile.

Traces of the spread of Christianity outside Europe are also preserved here. Among them are a few letters dated 1743, written in Beijing by Jesuit superiors on behalf of Bishop Polycarp de Souza. Written in Latin and Chinese, they recount the theological tensions linked to syncretism—the blending of local beliefs and Christian doctrine.

The manuscript of the June 18 Appeal will be displayed alongside other testimonies of recent history. In 2021, two microcapsules, the size of grains of rice, were added. They contain strands of synthetic DNA encoded with the Declaration of the Rights of Man and the Declaration of Woman and the Female Citizen by Olympe de Gouges . Protected from air and humidity, these small reservoirs guarantee a lasting archiving of what is intended to be a symbol of the convergence of scientific and social advances.