Broadcast: Jan. 4-March 28, 1976. The third series of 'Upstairs, Downstairs' is set during the First World War and follows the experiences of the entire family and staff during that painful period between 1914-1918 when over 1 million British soldiers were killed or wounded on the Western Front. This series chronicles the beginning of the end of the British empire, as well as the social unrest beginning to affect the class system, as viewed through the microcosm of the Bellamy household: family and servants.