Root was born in
Chelmsford, Essex, to Ken and Maureen Root. Her father was an accountant, whilst her mother had performed in amateur dramatic productions as a child. Both were supportive of her ambitions to become an actor. She attended
Philip Morant School in
Colchester, studying drama at O Level; she joined the Essex Youth Theatre as a teenager. After graduating from the
Webber Douglas Academy of Dramatic Art, she began her career at the
Leeds Playhouse in 1983 when she played Essie in
George Bernard Shaw's ''The Devil's Disciple''. She was a remarkably complete actress even in her early twenties, when physically she looked little more than a child. With her dark soulful eyes she could command a stage, and the
Royal Shakespeare Company saw her talent very early on. She worked regularly with the RSC in
Stratford-upon-Avon and London from 1983 to 1991, including playing the role of Juliet to
Daniel Day-Lewis's Romeo; a very young Lady Macbeth; Cressida to
Ralph Fiennes's Troilus, and Rosaline to his Berowne. She also appeared as Jessica opposite
Ian McDiarmid's Shylock in
The Merchant of Venice. She also starred as Nina in
Chekhov's The Seagull at the
Barbican Theatre. In 1993, Root played Hilda Maxwell in ITV period drama
The Man Who Cried, opposite
Ciarán Hinds. The series, adapted from the novel by
Catherine Cookson, received positive reviews and was watched by 12.7 million viewers. In 1994, she appeared in a
BBC comedy mini-series
Love on a Branch Line as an ostensibly “mousy” secretary, Miss Mounsey, who, ultimately throwing off her apparent reticence, landed the leading character, Jasper Pye (
Michael Maloney). That same year, Root was sought by the actress
Emma Thompson for the role of
Marianne in
Sense and Sensibility, based on
the 1811 novel by
Jane Austen. She participated in a read through in London with the cast but was unable to take on the role (it would later go to
Kate Winslet) as she had already committed to star as
Anne Elliot in another Austen adaptation,
Persuasion. The film, made by the BBC for drama anthology series
Screen Two, reunited Root with
Ciarán Hinds, who played Captain Wentworth. It was broadcast on
BBC Two in April 1995, and later gained a limited cinematic release in the
United States, grossing over five million dollars. Well received by critics, it went on to win five
TV BAFTAs, including for
Best Single Drama. In 1996, she played Patricia “Pat” Green in
Breaking the Code. Root's character was inspired by
Bletchley code-breaker
Joan Clarke, and starred
Derek Jacobi as
Alan Turing. In 1998, Root starred in BBC crime drama ''
Mortimer's Law'', as Rachel Mortimer, a barrister who relocates to rural Wales to take up a vacant coroner's post. The series ran for six episodes but was not recommissioned. In 2000, she played Dolly in
Anna Karenina, and later appeared as Mrs. Davilow in
Daniel Deronda. That same year, Root returned to the stage in
Yasmina Reza's Conversations After a Burial at the
Almeida Theatre. She also made guest appearances in various crime dramas, including
A Touch of Frost, ''
Foyle's War, Waking the Dead
, Poirot
and Midsomer Murders. In 2004, she appeared in ten episodes of period drama The Forsyte Saga
as Winifred Dartie. The following year, she featured in the docudrama Julian Fellowes Investigates
, playing murder victim Vera Sidney. In 2006, she portrayed Alice Hoschede, wife of Impressionist painter Claude Monet, in the BBC miniseries The Impressionists
. She also made her third appearance at the Almeida Theatre as Polina Bardin in Enemies'' by
Maxim Gorky, in a new interpretation by
David Hare. In 2008, Root was cast as Sarah in
Alan Ayckbourn's The Norman Conquests. It was first staged at the
Old Vic Theatre in London, before making its
Broadway transfer to the
Circle in the Square Theatre in
New York. The production, directed by
Matthew Warchus, was positively received by critics, and gained seven
Tony nominations, winning
Best Revival. Root was nominated for
Best Featured Actress in a Play; her performance was described as “remarkable” by
The New York Times. The cast were also nominated for an
Olivier Award for
Best Company Performance. In 2011, she starred as Hester Collyer in a stage production of
The Deep Blue Sea at the
Chichester Festival Theatre. She also played Amanda in
Margaret Thatcher biopic
The Iron Lady opposite
Meryl Streep and continued to make further guest appearances in television crime dramas, such as
DCI Banks,
The Tunnel and
Death in Paradise. In 2016, she appeared as Cecy in wartime comedy drama
Their Finest. In 2017, Root featured in an episode of hit BBC drama
Sherlock as Emma Welsborough. Later that same year, she starred as
Queen Victoria in historical drama
The Black Prince; the film explored the complex relationship between Victoria and
Duleep Singh, the last Maharajah of the Sikh Empire. In 2018, she played Carol Finch in six episodes of
ITV drama
Unforgotten, and Virginia Scott-Watson in
Patrick Melrose. On stage, she played governess Miss Madrigal in a
Chichester Festival Theatre production of
The Chalk Garden. In 2020, she appeared on television in popular
BBC drama
Call the Midwife and ITV thriller miniseries
The Sister, and on film in British drama
Summerland as social worker Mrs Lawrence. In 2021, she played Sister Brumfett in one episode of
Dalgliesh. The following year, she played Cynthia in a
film adaptation of
Alan Bennett's 2018 play
Allelujah!. She also appeared in BBC mystery thriller
The Capture. In 2023, Root featured in two episodes of romantic comedy drama series
You & Me. She also had a supporting role in true-life crime drama
The Sixth Commandment, based on the murder of
Peter Farquhar. Root played Farquhar's sister-in-law Sue Farquhar. In 2024, she featured in three episodes of black comedy drama
Baby Reindeer, which premiered on Netflix to critical acclaim. The series went on to win six Primetime Emmys and two Golden Globes. Later that year, she portrayed English abbess
Elizabeth Zouche in four episodes of BBC historical drama series
Wolf Hall: The Mirror and the Light, based on the novel by
Hilary Mantel. In 2025, Root appeared in the penultimate episode of long-running
ITV crime drama
Vera as Deena Corbridge. She is set to feature in upcoming British crime thriller
Lazarus for
Amazon Prime; filming for the series began in February 2024. ==Philanthropy==