The major plot in season two involves the Crawleys opening up Downton to serve as a convalescent hospital for soldiers wounded during the "Great War." In real life, Highclere Castle and its stewards, the Carnavons, did the exact same thing. As shown in a BBC featurette, the Countess of Carnavon, like the fictional Countess of Grantham, oversaw the transformation of the estate into a temporary hospital to support the war effort.