Marsh's 2000 film about the death of Henry VIII, Monarch, was re-released in cinemas in 2014.
With Eileen Atkins, Marsh created the British period dramaUpstairs, Downstairs and played the role of the house parlourmaidRose Buck for the duration of the series, from 1971 until 1975. The programme was screened internationally and received numerous awards including two BAFTA awards, two Royal Television Society awards, eight Emmys and a Golden Globe. Marsh received a Royal Television Society award in 1971 and an Emmy Award for Outstanding Lead Actress for her role in 1975, and was nominated for the same award on three more occasions – 1974, 1976, and (for the show's revival) in 2011. She also received awards from the American Drama Centre and American Drama Critics Circle for the role as well as two Golden Globe Award nominations.
She and Atkins created The House of Eliott, another television series broadcast between 1991 and 1994. This time, Marsh did not act in the series, but she did write some of the episodes.
Marsh served as the presenter for International Animation Festival, an American public television series featuring award-winning animated short films from around the world. The thirteen-part series was broadcast in 1975 on PBS.[2]
From 2000 until 2002, Marsh appeared in The Ghost Hunter. Her many stage credits included the West End stage revival of Boeing Boeing at the Comedy Theatre in 2007 and in Peter Hall's production of The Portrait of a Lady in 2008. She made an appearance in the 2008 BBC adaptation of Jane Austen's Sense and Sensibility; played the recurring character Lizzie Galbraith alongside Joanna Lumley as Davina Jackson (the lead character) in Babycow Productions' Sensitive Skin, which aired on BBC Two in 2005 and 2007. She appeared in BBC Four's Crooked House in December 2008 in a role written for her by Mark Gatiss.
A three-part revival of Upstairs, Downstairs was commissioned by the BBC with the first episode broadcast on BBC One on 26 December 2010. Marsh reprised her role as Rose Buck, who had returned to London to run an agency for domestic servants after a period spent nursing her mother in Suffolk. Eileen Atkins, who co-created the original series with Marsh, also starred in the revived series. It was set in the same London house as the original ITV series, 165 Eaton Place, resuming in 1936.[citation needed] Subsequently, a six-part second series was commissioned, and began transmission in February 2012 with Marsh's character appearing less frequently due to the stroke suffered by the actress.[3]
Marsh has written several books: Fiennders Abbey, The House of Eliott, and Iris.[4]
On 3 October 2011, the BBC announced that Marsh had suffered a minor stroke and would miss the beginning of the second series of Upstairs, Downstairs.[3] She was ultimately able to appear in only two scenes over the series.[citation needed] A third series was not commissioned.[9]