A war novel by Ford Madox Ford is among books doing well out of ITV's hit series, as publishers cash in on Downton Abbey's success in America.
The second series of Downton Abbey, Julian Fellowes' period drama set in a stately home in Edwardian England is on course to become a huge hit in America.
On Sunday, 4.2 million people in the US turned on to watch the first in the 10 hour series created by ITV, which is being broadcast on PBS. PBS's audience figures usually average at around two million.
The number of viewers doesn't top those of US TV giants such as House and Grey's Anatomy, but they are high for a public service broadcaster such as PBS.
US critics have responded positively to the series. The New York Post gave the first episode four stars, saying that the series "seamlessly moves between the horrors of war and the gentility of life in the show’s titular 100-room manor."
The Wall Street Journal wrote: "By the time viewers are halfway through the first episode, it will be clear that those 'Downton' fans who waited impatiently for season two will be more than amply rewarded."
Film industry magazine Variety also ran an excellent review: "Julian Fellowes has created such a vivid group of characters and assembled such an impeccable cast – effortlessly oscillating from comedy to drama – that the hours fly by, addictively pulling viewers from one into the next."
The Downton craze is so strong that US book publishers have started to bring out books which specifically relate to the series.
The New York Times quotes Stephen Morrison, the editor in chief and associate publisher of Penguin Books as saying he had been planning which books to release around the second series' premiere since last year: “We’re just riding that ‘Downton Abbey’ wave.” he said.
Twitter is being used by publishers to suggest books related to Edwardian England or World War One to Downton fans.
Among the books reported to be selling well are a new edition of Ford Madox Ford's war novel Parade's End, Love in a Cold Climate by Nancy Mitford and copies of The Decline and Fall of the British Aristocracy by David Cannadine.
Last year the programme entered the Guinness Book of Records for the highest critical ratings for a TV show – the first time a British programme has won the award. Previously US series Mad Men, Sons of Anarchy and Modern Family set the record.
Downton Abbey and EastEnders went head to head in the fight for viewing figures on Christmas day in the UK. Despite early reports that the BBC's EastEnders had won the race, in fact an additional 3.5 million viewers recorded the Downton Abbey and watched it in the days following. This gave the episode a total of 11.6 million viewers.