 After entering service, "Ernest Renan" was assigned to the cruiser squadron of the Mediterranean Fleet, based in Toulon.In April 1912, she was assigned to the 1st Light Squadron, along with the two s.

At the outbreak of World War I in August 1914, "Ernest Renan" and the armored cruisers and were mobilized as the First Light Division and tasked with hunting down the German battlecruiser and her consort "Breslau".These ships, along with a flotilla of twelve destroyers, was to steam to Philippeville on 4 August, but the German ships had bombarded the port the previous day.