Who was the President of France throughout World War I?

Raymond Nicolas Landry Poincaré (20 August 1860 – 15 October 1934) was a French statesman who served three times as 58th Prime Minister of France, and as President of France from 1913 to 1920. He was a conservative leader, primarily committed to political and social stability.

On 28 June 1914, Poincaré was at the Longchamps racetrack when he received news of the assassination of Archduke Franz Ferdinand in Sarajevo. The President remarked that the assassination was a tragedy, ordered an aide to draft a message of condolence to the people of Austria-Hungary.

On 31 July the German ambassador in Paris, Count Wilhelm von Schoen, presented an ultimatum warning that, if Russian mobilisation continued, Germany would attack both France and Russia within the next 12 hours. The ultimatum also demanded that France abrogated at once the alliance with Russia, allow German troops to march into France unopposed and turn over the fortresses in Verdun and Toul to the Germans to be occupied as long as Germany was at war with Russia.

After Germany declared war on France following the rejection of the ultimatum, Poincaré appeared before the National Assembly to announce that France was now at war forming the doctrine of the "union sacrée" (a political truce in France during World War I) in which he announced that: "nothing will break the "union sacrée" in the face of the enemy."