Question: Who passed away first, Manfred von Richthofen or Cedric Popkin ?

Context paragraphs:
Cedric Popkin: Cedric Bassett Popkin (Born 20 June 1890, died 26 January 1968) is considered the person most likely to have killed German ace Manfred von Richthofen — also known as the "Red Baron" — on 21 April 1918.  Popkin was an anti-aircraft (AA) machine gunner with the First Australian Imperial Force (AIF), during World War I.

Richthofen (film): Richthofen (aka Richthofen, The Red Knight of the Air and Richthofen, The Red Ace of Germany) is a 1927 German silent war film directed by Desider Kertesz and Peter Joseph.  The film was subsequently re-mastered with sound and music effects and re-released in the United States in 1929.  The film stars Georg Burghardt, Sybil Moore and Arne Molander.  "Richthofen" was the first film to portray the life of the First World War fighter pilot Manfred von Richthofen.

Ferdinand von Richthofen: Ferdinand Freiherr von Richthofen (5 May 18336 October 1905), better known in English as Baron von Richthofen, was a German traveller, geographer, and scientist.  He is noted for coining the terms "Seidenstraße" and "Seidenstraßen" = "Silk Road(s)" or "Silk Route(s)" in 1877.  He also standardized the practices of chorography and chorology.  He was an uncle of the World War I flying ace Manfred von Richthofen, best known as the "Red Baron".

Bolko von Richthofen: Bolko von Richthofen (September 13, 1899 – March 18, 1983) was a German archaeologist and a distant relative of the family of Manfred von Richthofen, the "Red Baron".  He is sometimes confused with his distant cousin and namesake, Karl Bolko von Richthofen (1903–1971) – the youngest brother of the fighter ace.

Manfred von Richthofen (sports official): Manfred von Richthofen (4 February 1934 – 1 May 2014) was a German hockey player and coach.  He was also an honorary President of German's national Olympic federation.  He was the nephew of World War I German pilot Manfred von Richthofen (the "Red Baron").  His career began during the 1950s.  He retired in 2006.  Richthofen was born in Berlin, Germany.

Lothar von Richthofen: Lothar Freiherr von Richthofen (born Lothar Siegfried Freiherr von Richthofen; 27 September 1894 – 4 July 1922) was a German First World War fighter ace credited with 40 victories.  He was a younger brother of top-scoring ace Manfred von Richthofen (the "Red Baron") and a distant cousin of Luftwaffe Field Marshal Wolfram von Richthofen.

Hermann von Richthofen: Hermann Freiherr von Richthofen, GCVO (born 20 November 1933 in Breslau) is a German diplomat.  He is a great nephew of Manfred von Richthofen, the "Red Baron".

Snowy Evans: Willy John "Snowy" Evans (  1891 –1925) was a Lewis machine gunner in the Royal Australian Artillery (RAA) during World War I.  Unsolved History, produced by Discovery Channel credited him with firing the shot that killed Manfred von Richthofen ("The Red Baron"), near Vaux-sur-Somme, France on 21 April 1918.  However, most sources attribute the feat to Sergeant Cedric Popkin of the 24th Machine Gun Company.  Other sources have suggested that Gunner Robert Buie, also of the 53rd Battery, fired the fatal shot, but there is now little support for this theory.

Manfred von Richthofen: Manfred Albrecht Freiherr von Richthofen (2 May 1892 – 21 April 1918), also known as the "Red Baron", was a fighter pilot with the German Air Force during World War I.  He is considered the ace-of-aces of the war, being officially credited with 80 air combat victories.

Manfred von Richthofen (general): Karl Ernst Manfred Freiherr von Richthofen (24 May 1855 – 28 November 1939) was a German "General der Kavallerie" (General of the Cavalry) during World War I and recipient of the order Pour le Mérite, known informally as the Blue Max.  Richthofen was a great uncle of his more famous namesake Manfred von Richthofen, known as the Red Baron, who was his godson and named after him.

Supporting paragraphs: Cedric Popkin Manfred von Richthofen
Answer: Manfred von Richthofen