German airships had bombed Paris for the first time on the 5th of August, but due to skillful blocking actions it was not until th 7th of October that German troops first set foot in the city. This gap between these dates was exploited by the German Air force however, meaning that whilst the city was defensible, it had suffered almost constant raids and was therefore not impregnable. The Battle of Paris was hard fought, lasting from the 7th of October 1914 to the 3rd of January 1919, and was one of the most costly battles of the entire war.