After graduating, he took up acting full-time and made his professional stage debut in 1983, playing Tim Allgood in Michael Frayn's Noises Off, which ran for a year at the Savoy Theatre.

In 1991, he won his first major television role playing Mark Taylor in the semi-autobiographical BBC sitcom Joking Apart, written by Steven Moffat.

In the following years he starred in the television dramas The Pillars of the Earth (2010), Downton Abbey (2010) and Hattie (2011) and joined the cast of Wild at Heart in 2012.

[1] He compared the time he and his brother, who were Catholics, spent at the Anglican boarding school to Lord of the Flies; "we were incarcerated in a huge, stinking, Georgian house, where we were treated very brutally".

[9] He had first become interested in acting when his family saw a pantomime at the Gaiety Theatre in Dublin and he watched actors waiting for their cues in the wings.

[10] He spent much of his time there performing in the Cambridge Footlights alongside Hugh Laurie, Rory McGrath and Emma Thompson.

[7] After leaving Cambridge, Bathurst spent a year touring Australia in the Footlights Revue Botham, The Musical, which he described as "a bunch of callow youths flying round doing press conferences and chat shows".

[7][13] Although he enjoyed his work with Footlights, he did not continue performing with the group, worrying that he would be "washed up at 35 having coat-tailed on their success through the early part of [his] career".

[9] His first professional role out of university was in the BBC Radio 4 series Injury Time, alongside fellow Footlights performers Rory McGrath and Emma Thompson.

[14] Bathurst's professional stage debut came the next year when he joined the second cast of Michael Frayn's Noises Off at the Savoy Theatre.

[18] He continued to make minor appearances in television throughout the 1980s; in 1987, he auditioned for the role of Dave Lister in the BBC North science fiction sitcom Red Dwarf.

The part eventually went to Craig Charles but Bathurst was given a role in the first episode of the first series as Frank Todhunter, second officer on the ship, who is killed in the first ten minutes.

Ten years later, Bathurst was invited to reprise the role when a storyline in the series allowed former characters to return, but filming commitments prevented him from appearing.

[21] The role is his favourite of his whole career; he has described it as "the most enjoyable job I will ever do" and considers several episodes of the series to be "timeless, beautifully constructed farces which will endure".

[19] Bathurst is often recognised for his appearance in this series, mentioning that "Drunks stop me on public transport and tell me details of the plot of their favourite episode".

[22] As punishment for arriving late for the series one press launch at the Café Royal in Regent Street, London, writer Steven Moffat pledged to write an episode in which Mark is naked throughout.

[20] Between 1991 and 1995, Bathurst also appeared on television in No Job for a Lady, The House of Eliott and The Detectives and on stage in The Choice, George Bernard Shaw's Getting Married at Chichester with Dorothy Tutin and Gogol's The Nose adapted by Alastair Beaton, which played in Nottingham and Bucharest.

Bathurst "wobbled, missed the camera and crashed into the pavement", leading director Simon Delaney to exclaim it was the funniest thing he had ever seen.

[15][21] In another episode, David buys a racehorse – ostensibly as a birthday present for his wife – in a plot born out of Bathurst's own love of horseracing.

Between 1998 and 2003, he made television appearances in Goodbye, Mr Steadman (2001), starring opposite Caroline Quentin as a shy and unassuming teacher who has been declared dead after one of his pupils erases all computer records relating to him and in the adaptation of White Teeth (2002).

[25] In the Daily Telegraph, Charles Spencer described his role as Tesman as a "weird casting choice" but called his acting "a brave stab".

[27] In 2003, he returned to theatre for the first time in four years to play Vershinin in The Three Sisters, opposite Kristin Scott Thomas and Eric Sykes.

[28] In 2005, the second series of My Dad's the Prime Minister was broadcast, now moved to a Friday night time slot to take advantage of the adult humour.

Bathurst was pleased that this white-collar worker had an emotional side, in comparison to David Marsden, whom he used as a yardstick when accepting those sorts of roles.

The play ran at the Arts Theatre between October and November 2007 and featured Bathurst interacting with other characters projected onto a screen behind him.

[31] He reprised the role in an international tour from September to November 2008, playing in Melbourne, Sydney, Hong Kong, Singapore and Dubai.

Between January and April 2010, Bathurst starred as Garry Essendine in a national touring revival of Noël Coward's Present Laughter.

[36] Present Laughter was the first time Bathurst had appeared in a Coward play and he was cast in another, Blithe Spirit, later in the year, as Charles Condomine.

On television in 2010, Bathurst starred as Percy Hamleigh in the German-Canadian miniseries The Pillars of the Earth and had a recurring role as widower Sir Anthony Strallan in the period drama Downton Abbey.