Streeton believed that Amiens, the key of the west was one of his most important works as an Official war artist. The title refers to the events of 8 August 1918 and the fighting in the Somme area that led up to this day. During the First World War, Amiens was significant as an administration and communication centre since all railways and roads crossed through it. Capturing the city became a principal objective for the Germans. From March to April 1918 they were driving towards the city, however the Australians' defence of Villers-Bretonneux prevented any further advance and thereafter Amiens became a safe base area for the allied forces. Streeton shows Amiens lying peacefully amongst green trees, with the great Cathedral in the distance. The gunfire at the horizon alludes to the city's vulnerability and strategic importance as 'the key of the west'.