Question: What Welsh actor starred in The Edge of Love with Keira Knightley?

Context articles: Collateral Beauty
The Edge of Love
Red Nose Day Actually
Matthew Rhys
Never Let Me Go (2010 film)
Dark plum Vera Wang dress of Keira Knightley
Last Night (2010 film)
Pure (2002 film)
The Walls
Begin Again (film)

Collateral Beauty is a 2016 American drama film directed by David Frankel and written by Allan Loeb.
 The film stars an ensemble cast of Will Smith, Edward Norton, Keira Knightley, Michael Peña, Naomie Harris, Jacob Latimore, Kate Winslet, and Helen Mirren.
 It follows a man who copes with his daughter's death by writing letters to time, death, and love.
The Edge of Love is a 2008 John Maybury drama film starring Keira Knightley, Sienna Miller, Cillian Murphy and Matthew Rhys from a script by Sharman Macdonald, Knightley's mother.
 Originally titled "The Best Time of Our Lives", the fictional story concerns the famous Welsh poet Dylan Thomas (played by Rhys), his wife Caitlin Macnamara (played by Miller) and their married friends, the Killicks (played by Knightley and Murphy).
 It was an official selection at the Edinburgh International Film Festival.
Red Nose Day Actually is a 2017 British romantic comedy television short film, acting as both a sequel to the 2003 feature film "Love Actually", and a part of the fund-raising event Red Nose Day 2017.
 "Love Actually" writer and director Richard Curtis returns alongside cast members Hugh Grant, Liam Neeson, Colin Firth, Andrew Lincoln, Chiwetel Ejiofor, Keira Knightley, Martine McCutcheon, Bill Nighy, Thomas Sangster, Lúcia Moniz, Olivia Olson, Marcus Brigstocke, and Rowan Atkinson.
Matthew Rhys Evans (born 8 November 1974), known professionally as Matthew Rhys, is a Welsh actor.
 He is best known for his Emmy-nominated role as Philip Jennings on the FX drama series "The Americans".
 He also starred as Kevin Walker on the ABC television drama "Brothers & Sisters", and as Dylan Thomas in "The Edge of Love".
Never Let Me Go is a 2010 British dystopian romantic drama film based on Kazuo Ishiguro's 2005 novel of the same name.
 The film was directed by Mark Romanek from a screenplay by Alex Garland.
 "Never Let Me Go" is set in an alternative history and centres on Kathy, Ruth and Tommy portrayed by Carey Mulligan, Keira Knightley and Andrew Garfield respectively, who become entangled in a love triangle.
 Principal photography began in April 2009 and lasted several weeks.
 The movie was filmed at various locations, including Andrew Melville Hall.
 "Never Let Me Go" was produced by DNA Films and Film4 on a US$15 million budget.
The dark plum Vera Wang dress of Keira Knightley refers to the evening gown worn by British actor Keira Knightley at the 78th Academy Awards on March 5, 2006.
 The full-length taffeta dress was created by designer Vera Wang and had a single shoulder strap and fishtail skirt.
 It was accessorised with a Bulgari necklace.
Last Night is a 2010 drama romance film written and directed by Massy Tadjedin.
 It stars Keira Knightley, Sam Worthington, Eva Mendes, and Guillaume Canet.
 The film's official trailer was released on November 6, 2010.
 It was released both in theaters and video-on-demand on May 6, 2011 in the United States.
 The film centers on Joanna (Keira Knightley) and Michael Reed (Sam Worthington), a successful and happy couple.
 They are moving along in their lives together until Joanna meets Laura (Eva Mendes), the stunningly beautiful colleague whom Michael never mentioned.
 While Michael is away with Laura on a business trip, Joanna runs into an old but never quite forgotten love, Alex (Guillaume Canet).
 As the night progresses and temptation increases, each must confront who they really are.
Pure is a 2002 British film directed by Gillies MacKinnon.
 It starred Molly Parker, Harry Eden, David Wenham and Keira Knightley.
The Walls are an Irish rock band.
 They were formed in 1998 by two ex-members of The Stunning – brothers Steve and Joe Wall.
 Their debut album "Hi-Lo" was released in 2000 and included the singles "Bone Deep", "Something's Wrong" and "Some kind of a Girl".
 U2 invited The Walls to support them at their second show in Slane Castle in 2002 after the band sent them copies of their debut.
 A number of songs from "Hi-Lo" featured in movies: Goldfish Memory, On the Edge, and Dead Bodies.
 In 2002 they released the single "To the Bright and Shining Sun".
 It was used on an Irish TV commercial and became a hit in Ireland.
 The subsequent album "New Dawn Breaking" (2005) included "To the Bright and Shining Sun" and three other singles: "Drowning Pool", "Passing Through" and "Black and Blue".
 The 2013 movie Begin Again starring Keira Knightley and Mark Ruffalo features "Drowning Pool" over the opening credits.
 The first track on the album "Open Road" proved a favourite with Nic Harcourt on his KCRW show "Morning Becomes Eclectic" and he invited the band to play a session on the show in 2006.
 They played SXSW in Austin, Texas, a few days beforehand.
 The following year the band travelled to Australia and played their first shows there, opening up for Crowded House on the latter's first reunion gigs.
 The Walls opened the shows in Sydney and Melbourne and also performed their own gigs in both of those cities.
 The band's third album "Stop the Lights" was released in 2012.
 The first single "Bird in a Cage" became a firm favourite with Irish radio, in particular with Irish DJ Tony Fenton who championed them.
 The second single was the title track "Stop the Lights", an autobiographical story of a motorbike crash.
 A video was shot for the song in the brother's hometown, Ennistymon, and in the Dublin mountains.
 In March 2013 the band played their first shows in Russia and performed live on the Evening Urgant show.
 They returned the following year.
Begin Again is a 2013 American musical comedy-drama film written and directed by John Carney and starring Keira Knightley and Mark Ruffalo.
 Knightley plays a singer-songwriter who is discovered by a struggling record label executive (Ruffalo) and collaborates with him to produce an album recorded in public locations all over New York City.