[19] Marshall began playing guitar aged thirteen and started a ZZ Top cover group called Gobbler's Knob.

[20][3] While the other members of Mumford & Sons were influenced by jazz, Marshall described the genre in 2013 as "the lowest form of art".

[20] He was inspired to play banjo after seeing O Brother, Where Art Thou?, switching to folk music and wearing his hair in dreadlocks.

[20][22] Marshall, a multi-instrumentalist, has said that he chose to focus on banjo over guitar because there were fewer banjoists and so it was easier for him to get session jobs.

[23] In the early 2000s, Marshall was in a bluegrass sleaze rap band[24] called Captain Kick and the Cowboy Ramblers, who had songs such as "Jesse the Gay" and "Country London".

[28] The jam nights attracted a number of musicians who had an affinity for earthy acoustic music,[29] including Noah and the Whale and Laura Marling.

"[31] Marshall played the banjo, guitars, dobro, and provided backing vocals, for the group,[32][33] and was often identified as the comic relief of the line-up.

"[45] It was released to minimal attention but steadily garnered more positive reviews,[2][46][47] and while Deusner criticized the album as derivative, he was impressed that "there are some unexpected textures, mostly courtesy of some guy calling himself Country Winston playing banjo and dobro.

[21][48] They followed the album with near-constant touring, cementing their presence,[2] though concert reviews were also mixed, criticizing the repetitiveness of the samey setlist while acknowledging the crowd's enjoyment.

[49][50][51] Chris Richards of The Washington Post added that the musicians' stage presence, particularly Marshall "thrusting his pelvis like a bluegrass Rick James", was irritating.

Self-titled with all three acts' names, it saw generally warm reviews that praised Marshall's dueling-banjo additions to songs.

[59] Babel became the quickest-selling album of the year, and the growing success of Mumford & Sons led to more detraction, with the band, and its banjo specifically, often criticized as inauthentic; Marshall told The Guardian that he disagreed, saying they are authentic because they play music that they enjoy and at which they are good.

[60] The band embraced other criticisms, creating a tongue-in-cheek music video for single "Hopeless Wanderer", parodying their own image.

[64] The band went on hiatus in 2013,[65] but contributed to a compilation album by Idris Elba released in 2014, re-recording their song "Home" with Thandiswa Mazwai.

[66] Marshall sang lead vocals on the song "Fool You've Landed",[75] which he co-wrote with then-girlfriend Dianna Agron and Beatenberg's Matthew Field.

The music draws more on their adult life experiences than their previous work, with the Evening Standard noting that during its creation Marshall got married but also experienced depression.

[88][90][91] In March 2021, Marshall faced criticism for lauding Unmasked: Inside Antifa's Radical Plan to Destroy Democracy, a book written by conservative American journalist and social media personality Andy Ngo.

[92][93] Later that month, Marshall apologised for praising the book and stated that he would be taking a break from the band "to examine [his] blindspots";[94] in June 2021, he wrote an essay defending his support for Ngo, discussing the reaction to his apology for the tweet, and announcing that he would be permanently leaving Mumford & Sons so that he could exercise free speech about politics without involving his former bandmates.

[17][95][96] In a 2022 interview with The Sunday Times Magazine he said that what made it hard to leave the band was that he had thought they would still be playing together in their sixties.

Desolation, recording music and performing shows with Ronnie Vannucci Jr. of The Killers, Tom Hobden of Noah and the Whale, and Jesse Quin and Tim Rice-Oxley of Keane.

[99] Marshall then joined a different, temporary, supergroup called Salvador Dalí Parton in October 2013, with fellow musicians Gill Landry of Old Crow Medicine Show; Mike Harris of Apache Relay; Jake Orrall of JEFF the Brotherhood; and Justin Hayward-Young of the Vaccines.

[116] The podcast was promoted as Marshall interviewing people working in creative industries "to find out what indeed is the state of the arts.

"[117][118] By October 2023, 45 episodes had been published, including interviews with Laurence Fox, Jordan Peterson and Candace Owens.

"[6] The existence of the British nu-folk scene has been credited to Marshall, as its most successful acts – Marling, Flynn, Hayward-Young, Noah and the Whale, Alan Pownall, King Charles, Alessi's Ark, Peggy Sue – all "graduated" from performing at Bosun's Locker on the folk jam nights that he ran, reportedly starting them as a way to play banjo.

[124] Marshall dated Irish stylist Susan Cooney,[125] who dressed Mumford & Sons and Haim,[126] and in March 2012 attended the White House British State dinner with her.

[128] It was first reported that Marshall was dating American actress Dianna Agron in July 2015,[129] and the couple got engaged in late 2015.

[136] In 2022, Marshall said that after several album tours, the lifestyle had negatively affected him, leading him to start self-medicating with alcohol and to regularly take a mix of hard drugs, describing the time as "all a bit of a blur"; he got sober in 2019, saying this gave him clarity and energy.

It's a massive change.On 7 July 2022 he was a guest on the BBC's political programme Question Time, discussing the resignation of British Prime Minister Boris Johnson which had been announced that day.