On this date, and for the next two days, in August 1944, the capital city of France was finally freed from German occupation. The story of the liberation of Paris is a remarkable one, well chronicled by Larry Collins and Dominique Lapierre in their book Is Paris Burning? If you haven't read it, I highly recommend it.
The story's too long and complex to tell here, but a summary may be found in Wikipedia. The video clip below uses footage shot during the liberation of the city to tell the story in brief.
Hitler had ordered the destruction of all monuments and landmarks in Paris before its evacuation, so that the Allies would liberate only a field of ruins. We may be grateful that the German garrison commander, General der Infanterie Dietrich von Choltitz, did not obey his orders, but instead did his utmost to hand over the city intact, despite enormous obstacles. The intact, beautiful city may perhaps be regarded as his memorial.