The August 1914 issue of L'Univers Israélite contained the following notice: "Since our editor and all our subeditors have joined, or will shortly join, their battle stations, the publication of our magazine has been suspended."
The magazine is on show at Les Juifs dans la Grande Guerre (The Jews in the Great War), an exhibition now on at the Château de Péronne, in the Somme département.

The magazine's laconic notice to its readers was typical of the state of mind to be found throughout the Jewish community in Europe: in both east and west, 1.5 million Jews willingly went to the front, fired as they were by the general atmosphere of patriotic enthusiasm. "The Jews gave of their best for the fatherlands in that war," we read in La Comédie de Charleroi, by Pierre Drieu La Rochelle, a veteran of the first world war who later became a notorious anti-semite.

In their choice of 150 documents, the exhibition's organisers, Thomas Compère-Morel and Philippe Landau, curator at the Paris Consistory, focus particularly on the French and German communities. France's 180,000 Jews, many of whom had lost their Jewish faith and were closely attached to the republic that had emancipated them, had just emerged from the traumatic Dreyfus affair. They nevertheless donned their uniforms enthusiastically and trotted out the nationalist slogans of the time.

In synagogues rabbis expressed the wish that divine justice would come to the help of the army. The anti-semitic rags that stigmatised the Jews as "war profiteers" or "draft dodgers" were preaching in the wilderness. By the end of August 1914, 8,500 out of 30,000 Jewish immigrants who did not even have a French passport had joined the French army.

A photograph in the exhibition taken from L'Illustration magazine shows a rabbi standing next to a row of Protestant and Catholic chaplains. A painter, Lucien Lévy-Dhurmer, immortalised Rabbi Abraham Bloch, who later died at the front. He is depicted showing a cross to a dying Christian soldier. The painting came to symbolise the Sacred Union between church and state in the first world war.

In both France and Germany Jewish intellectuals tried to outdo each other in patriotism. They included the philosopher Henri Bergson and the sociologist Emile Durckheim, who lost a son in the war.

While anti-semitism continued to thrive in the ranks of the Russian armed forces and was perceptible in Germany, it was virtually unknown in the British, French and Italian armies. When peace came, memories of the Jews' commitment remained vivid in the French community.

And yet anti-semitism sprang up again throughout Europe, and particularly in France, as nationalism became more and more virulent. A little more than 20 years after the Treaty of Versailles the Vichy regime and Marshal Philippe Pétain, the hero of Verdun, renounced the Sacred Union. Jews who had fought in the first world war were thunderstruck.

On show in the exhibition is a letter that an outraged Jewish veteran wrote in October 1940 to a former comrade in arms, now interior minister, Marcel Peyrouton, after Pétain had introduced Vichy's first anti-semitic measures. Worse was to come.

· Les Juifs dans la Grande Guerre, Historial de la Grande Guerre, Château de Péronne, Péronne (Somme). Closed on Monday. Until March 31, 2003