Question: What did Malcolm Arnold complete first, "The Symphony No. 4," or, the score for, "The Bridge on the River Kwai"?

Context articles: Symphony No. 1 (Arnold)
Symphony No. 4 (Arnold)
Malcolm Arnold
The River Kwai March
The Bridge on the River Kwai
Symphony No. 2 (Arnold)
Philip Toosey
The Bridge over the River Kwai
Concerto for Group and Orchestra
Kitulgala

The Symphony No. 1, Op 22, is a symphony written by Malcolm Arnold in 1949.
 Arnold conducted the first performance at the Cheltenham Music Festival in 1951, with The Hallé Orchestra.
 A miniature score was published in 1952.
The Symphony No. 4, Op. 71 by Malcolm Arnold was finished on 13 July 1960.
 It is in four movements:
Sir Malcolm Henry Arnold, CBE (21 October 1921 – 23 September 2006) was an English composer.
 His output of works features music in many genres, including a cycle of nine symphonies, numerous concertos, concert works, chamber music, choral music and music for brass band and wind band.
 He wrote extensively for the theatre, with five ballets specially commissioned by the Royal Ballet, as well as two operas and a musical.
 He also produced scores for more than a hundred films, among these "The Bridge on the River Kwai" (1957), for which he won an Oscar.
"The "River Kwai" March" is a march composed by Malcolm Arnold in 1957.
 It was written as an orchestral counter-march to the "Colonel Bogey March", which is whistled by the soldiers entering the prisoner camp in the film "The Bridge on the River Kwai" and again near the end of the film when the bridge is formally dedicated.
 The Arnold march re-appears (without the "Colonel Bogey March") several times in the film and is repeated at the finale.
The Bridge on the River Kwai is a 1957 British-American epic war film directed by David Lean and starring William Holden, Jack Hawkins, and Alec Guinness, and featuring Sessue Hayakawa.
 Based on the novel "Le Pont de la Rivière Kwai" (1952) by Pierre Boulle, the film is a work of fiction, but borrows the construction of the Burma Railway in 1942–1943 for its historical setting.
 The movie was filmed in Ceylon (now Sri Lanka).
 The bridge in the film was near Kitulgala.
The Symphony No. 2, Op 40 by Malcolm Arnold is a symphony dating from 1953.
 Arnold composed the symphony on commission from the Bournemouth Winter Garden's Society.
 He dedicated the score to the Bournemouth Symphony Orchestra and conductor Charles Groves, who premiered the work on 25 May 1953.
Brigadier Sir Philip John Denton Toosey (12 August 1904 – 22 December 1975) was, as a lieutenant colonel, the senior Allied officer in the Japanese prisoner-of-war camp at Tha Maa Kham (known as Tamarkan) in Thailand during World War II.
 The men at this camp built Bridge 277 of the Burma Railway as later fictionalized in the book "The Bridge over the River Kwai" by Pierre Boulle, and since adapted into the Oscar-winning film "The Bridge on the River Kwai" in which Alec Guinness played the senior British officer, Lt. Colonel Nicholson.
 Both the book and film outraged former prisoners because Toosey did not collaborate with the enemy, unlike the fictional Lt. Colonel Nicholson.
The Bridge over the River Kwai (French: Le Pont de la Rivière Kwai ) is a novel by the French novelist Pierre Boulle, published in French in 1952 and English translation by Xan Fielding in 1954.
 The story is fictional but uses the construction of the Burma Railway, in 1942–43, as its historical setting, and is partly based on Pierre Boulle's own life experience working in Malaysia rubber plantations and later working for allied forces in Singapore and Indochina during World War II.
 The novel deals with the plight of World War II British prisoners of war forced by the Imperial Japanese Army to build a bridge for the "Death Railway", so named because of the large number of prisoners and conscripts who died during its construction.
 The novel won France's "Prix Sainte-Beuve" in 1952.
The Concerto for Group and Orchestra is a concerto composed by Jon Lord, with lyrics written by Ian Gillan.
 It was first performed by Deep Purple and The Royal Philharmonic Orchestra conducted by Malcolm Arnold on 24 September 1969 and released on vinyl in December 1969.
 After the score was lost in 1970, it was performed again in 1999 with a recreated score.
 The 1969 performance was the first ever combination of rock music and a complete orchestra and paved the way for other rock/orchestra performances such as Metallica's "S&M" concert and Roger Waters's "The Wall – Live in Berlin" performance.
Kitulgala is a small town in the west of Sri Lanka.
 It is in the wet zone rain forest, which gets two monsoons each year, and is one of the wettest places in the country.
 Nevertheless, it comes alive in the first three months of the year, especially in February, the driest month.
 The Academy Award-winning "The Bridge on the River Kwai" was filmed on the Kelani River near Kitulgala, although nothing remains now except the concrete foundations for the bridge (and, supposedly, the submerged train cars that plunged into the river in the climactic scene).
 Kitulgala is also a base for white-water rafting, which starts a few kilometres upstream.