Question: What nationality were both Richard Llewellyn and Saki? 

Context paragraphs:
United States Ambassador to Mongolia: This is a list of United States Ambassadors to Mongolia.  The United States established diplomatic relations with then-People's Republic of Mongolia on January 27, 1987.  The Embassy in Ulaanbaatar was opened Apr 17, 1988, with Steven Mann as Chargé d'Affaires ad interim.  Richard Llewellyn Williams was the first ambassador to the Republic, and resided in the District of Columbia.  The current Mongolian ambassador to the United States is Altangerel Bulgaa, who succeeded Khasbazaryn Bekhbat when he was appointed on December 7, 2012.  The U.S. maintains its embassy in Ulan Bator.

How Green Was My Valley (TV drama serial): How Green Was My Valley is a BBC Television serial based on the novel by Richard Llewellyn, and features one of the last performances by Stanley Baker.  It was first shown in the UK from 29 December 1975 in six weekly parts, while producer Martin Lisemore also cast Siân Phillips in his next production, "I Claudius" (1976).

Welsh Mam: The Welsh Mam ("mam" means "mother" in Welsh) was an archetypal image of Welsh married women that emerged in 19th century industrial South Wales.  Described as "hardworking, ‘pious’ and clean, a mother to her sons and responsible for the home", this image of women was depicted in Richard Llewellyn's 1939 novel "How Green Was My Valley".  The mythologised Welsh Mam was seen as a matriarch ruling her household, but in reality many Welsh women were economically dependent upon male wage-earners, and suffered poverty and ill health exacerbated by regular childbearing.

Green, Green My Valley Now: Green, Green My Valley Now is a 1975 novel by Richard Llewellyn.  It is the final of three sequels to the better known "How Green Was My Valley".

Richard Atcherley: Air Marshal Sir Richard Llewellyn Roger Atcherley, {'1': ", '2': ", '3': ", '4': "} (12 January 1904 – 18 April 1970) was a senior Royal Air Force officer.  He served as Commander-in-Chief of the Royal Pakistan Air Force from 1949 to 1951.

Poison Pen (film): Poison Pen is a 1939 film directed by Paul L. Stein, starring Flora Robson, Reginald Tate and Ann Todd.  It was based on the 1937 play by Richard Llewellyn.

Bronwen: Bronwen (] ) is a Welsh feminine given name.  It is closely associated with the similar name "Branwen", which appears in medieval Welsh literature.  Used in Wales since the 19th century, it was introduced to the English-speaking public at large by a character in the Richard Llewellyn novel "How Green Was My Valley" (1939).

Saki: Hector Hugh Munro (18 December 1870 – 14 November 1916), better known by the pen name Saki, and also frequently as H. H. Munro, was a British writer whose witty, mischievous and sometimes macabre stories satirize Edwardian society and culture.  He is considered a master of the short story, and often compared to O. Henry and Dorothy Parker .  Influenced by Oscar Wilde, Lewis Carroll and Rudyard Kipling, he himself influenced A. A. Milne, Noël Coward and P. G. Wodehouse.

Richard Llewellyn: Richard Dafydd Vivian Llewellyn Lloyd (8 December 1906 – 30 November 1983), known by his pen name Richard Llewellyn, was a British novelist.

How Green Was My Valley: How Green Was My Valley is a 1939 novel by Richard Llewellyn, narrated by Huw Morgan, the main character, about his Welsh family and the mining community in which they live.  The author had claimed that he based the book on his own personal experiences but this was found to be untrue after his death; Llewellyn was English-born and spent little time in Wales, though he was of Welsh descent.  Llewellyn gathered material for the novel from conversations with local mining families in Gilfach Goch.

Supporting paragraphs: Richard Llewellyn Saki
Answer: British