 Construction of Diderot began on 26 December 1906 by Ateliers et Chantiers de la Loire in Saint-Nazaire and the ship was laid down on 20 October 1907. She was launched on 19 April 1909 and was completed on 1 August 1911. The ship was assigned to the First Division of the First Squadron (escadre) of the Mediterranean Fleet when she was commissioned. The ship participated in combined fleet maneuvers between Provence and Tunisia in May – June 1913 and the subsequent naval review conducted by the President of France, Raymond Poincaré on 7 June 1913. Afterwards, Diderot joined her squadron in its tour of the Eastern Mediterranean in October – December 1913 and participated in the grand fleet exercise in the Mediterranean in May 1914.
