(written from a Production point of view)
Arthur Christopher Orme Plummer, CC (13 December 1929 – 5 February 2021; age 91) was an actor who played General Chang in Star Trek VI: The Undiscovered Country. He also reprised the role of Chang for the video game Star Trek: Klingon Academy.
In a career spanning over sixty years, he earned two Tony Awards (out of seven nominations), two Emmy Awards (out of six nominations), an Academy Award nomination, an Academy Award, and numerous other accolades. Michael Dorn, who acted alongside Plummer in Star Trek VI, once described him as "an incredible actor". (Star Trek: The Magazine Volume 3, Issue 9, p. 19) Perhaps Plummer's most famous film role is that of Captain Georg von Trapp in the classic 1965 musical The Sound of Music, directed by Robert Wise (who went on to direct Star Trek: The Motion Picture). Plummer received his Academy Award in 2012 for Best Performance by an Actor in a Supporting Role for his work on the drama Beginners.
Early life and stage work
Born in Toronto, Ontario, Canada, Plummer initially studied to become a concert pianist, but turned to acting during his high school years. Beginning his professional acting career on the stage as well as in radio in his hometown of Montreal, Plummer made his New York stage acting debut in 1954. During his career, he acted in countless stage productions, particularly on Broadway and London's West End.
He made his Broadway debut in The Starcross Story in 1954. The following year, he performed in a Paris production of Medea co-starring opposite Dame Judith Anderson (whom Plummer called a "a little Tasmanian devil … who with one look could turn an audience to stone").  He returned to Broadway in late 1955 to work with Theodore Bikel in The Lark.
Plummer was first nominated for a Tony Award for his performance in the Broadway production of J.B. Although actor Pat Hingle played the title role when this play opened in 1958, the role was later given to James Daly. Plummer's subsequent Broadway credits included the lead roles in Arturo Ui (1963, with Elisha Cook) and The Royal Hunt of the Sun (1965).
He won his first Tony Award in 1974 for his performance in a musical adaptation of the classic tale of Cyrano de Bergerac simply called Cyrano, in which Plummer starred in the title role (a role he had previously played on television). Following his work on Cyrano, Plummer acted with Rene Auberjonois in The Good Doctor at the Eugene O'Neill Theatre. Plummer received another Tony nomination for his portrayal of Iago in a 1982 production of Othello, in which he worked alongside Kelsey Grammer, who played Cassio.
Plummer was again nominated for a Tony for No Man's Land in 1994. This was followed by a Tony Award-winning performance in Broadway's Barrymore in 1997 and a Tony Award-nominated portrayal of King Lear at New York City's Lincoln Center in 2004. He performed in a 2007 Broadway revival of Inherit the Wind, for which he received his seventh Tony Award nomination.
Plummer was just as active on film as in theater. He made his film debut in the 1958 Sidney Lumet drama Stage Struck, co-starring Star Trek: The Original Series guest actors Roger C. Carmel and John Fiedler. That same year, he starred in Wind Across the Everglades, and in 1964, he starred in The Fall of the Roman Empire. After his star-making turn in The Sound of Music, he appeared in such classic films as The Night of the Generals (1967), Battle of Britain (1969), Waterloo (1970), The Man Who Would Be King (1975), The Return of the Pink Panther (1975), and The Silent Partner (1978). He is also known for his portrayal of Detective Sherlock Holmes in 1979's Murder by Decree.
Plummer went on to co-star in such contemporary hits as Somewhere in Time (1980, with Bill Erwin and Susan French), Dragnet (1987, with Juliana Donald, Bruce Gray, Jimmie F. Skaggs, and Meg Wyllie), Malcolm X (1992, co-starring Albert Hall, Tim Kelleher, James MacDonald, and Craig Wasson), Wolf (1994), Dolores Claiborne (1995, with Bob Gunton), and Twelve Monkeys (1995, with Frank Gorshin). He also lent his voice to a number of animated films, most notably the Don Bluth productions An American Tail (1986, also featuring the voices of Phillip Glasser and Nehemiah Persoff) and Rock-A-Doodle (1991, with Stan Ivar and Phil Morris).
His many other diverse film credits range from co-starring with fellow Trek movie villain Malcolm McDowell in 1976's Aces High to working with Star Trek: Voyager's Jeri Ryan in Dracula 2000. He had supporting roles opposite Russell Crowe in two acclaimed dramas: first portraying 60 Minutes creator and media titan Don Hewitt in 1999's The Insider (with James Harper, Bruce McGill and Vyto Ruginis) and 2001's A Beautiful Mind (with Josh Pais). He was known to do family films, as well, such as LeVar Burton's Blizzard (2003).
Further proving his versatility, the busy Plummer had roles in recent films ranging from the epic Alexander (2004) and the action blockbuster National Treasure (2004, with Ron Canada and Don McManus) in 2004, to the romantic comedy Must Love Dogs (with Brad William Henke) and the historical drama The New World in 2005, to the thriller Inside Man (2006) and the romantic fantasy The Lake House in 2006 and 2007, respectively. In addition, Plummer co-starred with Star Trek: Deep Space Nine's Alexander Siddig in the 2005 political drama Syriana, in which Trek guest stars David Clennon and Robert Foxworth also appeared. More recently, Plummer starred in the acclaimed 2007 comic drama Man in the Chair, working with George Murdock.
Plummer starred in Terry Gilliam's 2009 film The Imaginarium of Doctor Parnassus, playing the title role. Production on this film was temporarily halted following the sudden death of Plummer's co-star, Heath Ledger.  Shooting on the film resumed in Vancouver, Canada, with Johnny Depp, Colin Farrell, and Jude Law taking over Ledger's role, with Ledger's footage to be preserved in the film.  The film wrapped on 22 April 2008. 
Plummer earned his first Academy Award nomination, as well as Golden Globe and Screen Actors Guild Award nominations, for his portrayal of Leo Tolstoy in the drama The Last Station.    Plummer also had voice-over roles in the 2009 computer animated films Up (composed by Michael Giacchino) and 9.
In 2011, Plummer appeared in the role of Monsignor Orelas in the vampire thriller Priest, based on the Korean comic book of the same name. His co-stars in this film included Mädchen Amick, Alan Dale, Brad Dourif, Reiner Schone, and Karl Urban. The same year he co-sttared in the American film adaptation of Stieg Larsson's The Girl with the Dragon Tattoo, directed by David Fincher. The film also featured Steven Berkoff in the cast. Plummer co-starred with Simon Pegg in 2014's Hector and the Search for Happiness, and appeared in 2015's Danny Collins and 2016's The Exception.
Plummer was cast as multi-millionaire J. Paul Getty in the 2017 thriller All the Money in the World. He replaced Kevin Spacey, who had already filmed his scenes as Getty, but was deleted from the film due to the allegations that he molested children, among them Plummer's A Beautiful Mind co-star Anthony Rapp when Rapp was 14 years old.
In 2019, Plummer appeared in the ensemble cast of the whodunit Knives Out, which also featured K Callan and the war film The Last Full Measure, which included John Savage and Robert Pine in the cast. The latter turned out to be his final live-action role, although he lent his voice to the animated film Heroes of the Golden Masks, to be released in 2021, which will also feature the voice of Ron Perlman.
Plummer worked with Frank Overton on an episode of The Alcoa Hour and with fellow Klingon player John Colicos in the 1962 Hallmark Hall of Fame production of Cyrano de Bergerac, with Plummer starring in the title role which he would reprise for the stage in the 1970s. (Plummer later co-starred with Colicos in the 1988 movie Shadow Dancing.) Another Hallmark production Plummer appeared in, Little Moon of Alban, featured one-time TOS guest Stephen Brooks and earned Plummer his first Emmy Award nomination.
Additionally, Plummer appeared in a number of TV mini-series, notably 1976's The Moneychangers, which co-starred Joan Collins and Jon Lormer, and 1983's The Thorn Birds, with Philip Anglim, Antoinette Bower, John de Lancie, Richard Kiley, Jean Simmons, and Meg Wyllie. Plummer received Emmy nominations for his performances in both of these series, winning his nomination for the former. Plummer's other mini-series include 1977's Jesus of Nazareth, 1986's Crossings, the latter also featuring Zach Galligan, Kelsey Grammer, and Herta Ware, 2000's Nuremburg (on which Gerald W. Abrams served as executive producer) and 2008's The Summit, with Bruce Greenwood.
Plummer was also nominated by the Emmy Awards for his portrayal in the title role of Hamlet in a 1964 TV movie and for his performance as Cardinal Bernard Law in the 2005 TV movie Our Fathers. Plummer additionally won an Emmy for Outstanding Voice-Over Performance for narrating the animated series Madeline. In 2010 he narrated the television documentary series Moguls & Movie Stars. For the episode "The Birth of Hollywood", Plummer received a Primetime Emmy Award nomination for Outstanding Voice-Over Performance in 2011.
Other Trek connections
In the 1950s, Plummer's understudy for a production of Henry V at the Stratford Shakespeare Festival was William Shatner. During the festival, Plummer fell ill and Shatner was forced to take the stage, giving Shatner his first big break. They also co-starred together in a 1957 Omnibus production of Oedipus, the King (with Plummer in the title role) and the 1979 made-for-television movie Riel. Another Star Trek VI actor he co-starred with prior to that production was David Warner in the 1977 film The Disappearance.
Plummer worked with Star Trek: The Next Generation guest actor Robin Gammell on at least three occasions: in the 1973 film The Pyx, the 1984 film Highpoint (with Saul Rubinek), and the 1997 TV movie The Arrow.