Question: Robert Armstrong-Jones the Welsh physician was what relation to Antony Armstrong-Jones, 1st Earl of Snowdon?

full_context: Document 1: John Roberts (missionary): Roberts was born in 1853 at Llewfllyd, in Dyserth, which was then considered in Flintshire but later placed in Denbighshire, in north Wales. Educated at Ruthin grammar school and St David's College, Lampeter (then affiliated with Oxford University), Roberts graduated in 1878. He was ordained a deacon by the Right Rev. George Augustus Selwyn in Lichfield Cathedral, and briefly served as a curate at Dawley Magna in Shropshire. However, Roberts yearned to become a missionary, possibly because of Selwyn's work in New Zealand. By year's end, Roberts had sailed to Nassau, Bahamas, where he was ordained a priest and made chaplain of St. Matthew Cathedral. Roberts concentrated his ministry among "coloured people" and lepers. However, those were already Christian, and the priest wanted greater challenges, particularly among American Indians.
Document 2: Antony Armstrong-Jones, 1st Earl of Snowdon: Antony Charles Robert Armstrong-Jones, 1st Earl of Snowdon, (7 March 1930 – 13 January 2017), commonly known as Lord Snowdon, was a British photographer and film maker. He was married to Princess Margaret, younger daughter of King George VI and the sister of Queen Elizabeth II.
Document 3: Anthony Armstrong Jones: Ronnie Jones (born June 2, 1949 in Ada, Oklahoma; died June 16, 1996) was an American country music singer known professionally as Anthony Armstrong Jones, a stage name that he took from the name of the British photographer who married Princess Margaret, Countess of Snowdon. A former professional golfer, Jones recorded four albums for Chart Records in that timespan, in addition to charting six times in the Top 40 on the "Billboard" country singles charts. His debut single was a No. 22-peaking cover of "Proud Mary," originally by Creedence Clearwater Revival, which served as the title track of his first album. Its second single was "New Orleans," originally recorded by Gary U. S. Bonds.
Document 4: Lady Sarah Chatto: Lady Sarah Frances Elizabeth Chatto (née Armstrong-Jones; born 1 May 1964) is the only daughter of Princess Margaret, Countess of Snowdon, and the 1st Earl of Snowdon. She is a niece of Queen Elizabeth II and the youngest grandchild of King George VI and Queen Elizabeth The Queen Mother.
Document 5: Ronald Armstrong-Jones: Major Ronald Owen Lloyd Armstrong-Jones MBE QC (18 May 1899 – 27 January 1966) was a British barrister and soldier and the father of Antony Armstrong-Jones, 1st Earl of Snowdon.
Document 6: Robert Armstrong-Jones: Sir Robert Armstrong-Jones, CBE (born Robert Jones; 2 December 1857 – 31 January 1943) was a Welsh physician and psychiatrist. He was the grandfather of Antony Armstrong-Jones, 1st Earl of Snowdon (d. 2017).
Document 7: David Armstrong-Jones, 2nd Earl of Snowdon: David Albert Charles Armstrong-Jones, 2nd Earl of Snowdon (born 3 November 1961), styled as Viscount Linley until 2017 and known professionally as David Linley, is an English furniture maker and the former chairman of the auction house Christie's UK. The son of Princess Margaret, Countess of Snowdon, and of Antony Armstrong-Jones, 1st Earl of Snowdon, he is a grandson of King George VI and is 18th in line of succession to the British throne, the first in line who is not a descendant of Queen Elizabeth II.
Document 8: Lady Margarita Armstrong-Jones: Lady Margarita Elizabeth Rose Alleyne Armstrong-Jones (born 14 May 2002) is the only daughter and youngest child of the Earl and Countess of Snowdon. She is the only granddaughter of Princess Margaret and the first of three granddaughters of the 1st Earl of Snowdon.
Document 9: Anthony Armstrong Jones: Ronnie Jones (born June 2, 1949 in Ada, Oklahoma; died June 16, 1996) was an American country music singer known professionally as Anthony Armstrong Jones, a stage name that he took from the name of the British photographer who married Princess Margaret, Countess of Snowdon. A former professional golfer, Jones recorded four albums for Chart Records in that timespan, in addition to charting six times in the Top 40 on the "Billboard" country singles charts. His debut single was a No. 22-peaking cover of "Proud Mary," originally by Creedence Clearwater Revival, which served as the title track of his first album. Its second single was "New Orleans," originally recorded by Gary U. S. Bonds.
Document 10: Robert Hotung: Sir Robert Ho Tung Bosman, {'1': ", '2': ", '3': ", '4': "} (22 December 1862 – 26 April 1956), better known as Sir Robert Hotung, was an influential Hong Kong businessman and philanthropist in British Hong Kong. Known as "the grand old man of Hong Kong", Hotung was knighted in 1915 and 1955.
Document 11: Robert William Jameson: Robert William Jameson, WS (1805–1868): A Writer to the Signet in Edinburgh, Town Councillor, newspaper editor, poet and playwright, Robert William Jameson was the father of Sir Leander Starr Jameson, South African statesman and prime minister, and the nephew of Professor Robert Jameson of the University of Edinburgh. Born in Edinburgh in 1805, Robert William was the son of Thomas Jameson, a wealthy shipowner, merchant and burgess of the city of Edinburgh, as recorded in Colvin, Vol. 1: 1-2 (1922). Colvin writes of Robert William's father and grandfather, both of whom were named Thomas Jameson, that:
Document 12: Sir James Reid, 1st Baronet: Sir James Reid, 1st Baronet, (23 October 1849 – 28 June 1923) was Physician in ordinary to three British monarchs. He is the subject of a 1987 biography by Michaela Reid, which has been reprinted several times.
Document 13: Charles Armstrong-Jones, Viscount Linley: Charles Patrick Inigo Armstrong-Jones, Viscount Linley (born 1 July 1999) is the only son of David Armstrong-Jones, 2nd Earl of Snowdon, and Serena Armstrong-Jones, Countess of Snowdon. He is a great-grandson of King George VI. He is heir apparent to the Earldom of Snowdon and 19th in line of succession to the British throne, after his father.
Document 14: John Donald (jewellery designer): John Donald is a British jeweller - designer whose work is strongly identified in the 1960s and 1970s in London. Princess Margaret and the Queen Mother purchased works by John Donald in the 1960s, having been introduced to him by Antony Armstrong-Jones, 1st Earl of Snowdon.
Document 15: Earl of Snowdon: Earl of Snowdon is a title in the Peerage of the United Kingdom. It was created in 1961, together with the subsidiary title Viscount Linley, of Nymans in the County of Sussex, by Queen Elizabeth II for her then brother-in-law, Antony Armstrong-Jones, who married Princess Margaret in 1960.
ground_truth: the grandfather