Question: Who is Ian Leslie, 21St Earl Of Rothes's paternal grandfather?

Knowledge 1: Ian Leslie, 21st Earl of Rothes
Ian Lionel Malcolm Leslie, 21st Earl of Rothes (10 May 1932 – 15 April 2005) was a Scottish nobleman.The eldest son of the 20th Earl and Beryl Dugdale, he was educated at Eton and was a Sub-Lieutenant in the Royal Naval Volunteer Reserve from 1953.In 1955 he married Marigold Evans-Bevan of Wales, daughter of Sir David Evans-Bevan.They had two sons: James (b. 1958) and Alexander (b. 1962). [SEP] Knowledge 2: Malcolm Leslie, 20th Earl of Rothes
Malcolm George Dyer-Edwardes Leslie, 20th Earl of Rothes (1902 – 1975) was a Scottish nobleman, and the head of Clan Leslie.He was the Earl of Rothes from 1927-1975 following the death of his father, Norman Leslie, 19th Earl of Rothes.His mother was Noël Leslie, Countess of Rothes, who not only survived the "Titanic" disaster, but took the till of a lifeboat and helped row survivors to the "RMS Carpathia".His son succeeded him in 1975 as the Earl of Rothes.On 17 July 1926, he married Beryl Dugdale, daughter of Lionel Dugdale of Crathorne, a former High Sheriff of Yorkshire, and sister of Thomas Dugdale, 1st Baron Crathorne.They had three children:He worked as Chairman of the National Mutual Life Assurance Society.He succeeded as the 20th Earl of Rothes on the death of his father in 1927.He served as a Representative Peer for Scotland until this system was abolished.The Earl died on 7 May 1975.The Rothes Chair in Preventive Ophthalmology was established at London University in his memory in 1977.
Knowledge 1: Ian Leslie, 21st Earl of Rothes
Ian Lionel Malcolm Leslie, 21st Earl of Rothes (10 May 1932 – 15 April 2005) was a Scottish nobleman.The eldest son of the 20th Earl and Beryl Dugdale, he was educated at Eton and was a Sub-Lieutenant in the Royal Naval Volunteer Reserve from 1953.In 1955 he married Marigold Evans-Bevan of Wales, daughter of Sir David Evans-Bevan.They had two sons: James (b. 1958) and Alexander (b. 1962). [SEP] Knowledge 2: George Leslie, 15th Earl of Rothes
George William Evelyn Leslie, 15th Earl of Rothes (8 November 1809 – 10 March 1841) was the son of Henrietta Leslie, 14th Countess of Rothes and George Gwyther.He was christened on 14 December at Saint Mary-St Marylebone Road, St Marylebone, London, England.
Leslie succeeded his mother Henrietta Anne, to the title Earl of Rothes, in 1819.On 7 May 1831, he married Louisa Susannah Jane Anderson Morshead, daughter of Henry Anderson Morshead, and they had issue:
Knowledge 1: Malcolm Leslie, 20th Earl of Rothes
Malcolm George Dyer-Edwardes Leslie, 20th Earl of Rothes (1902 – 1975) was a Scottish nobleman, and the head of Clan Leslie.He was the Earl of Rothes from 1927-1975 following the death of his father, Norman Leslie, 19th Earl of Rothes.His mother was Noël Leslie, Countess of Rothes, who not only survived the "Titanic" disaster, but took the till of a lifeboat and helped row survivors to the "RMS Carpathia".His son succeeded him in 1975 as the Earl of Rothes.On 17 July 1926, he married Beryl Dugdale, daughter of Lionel Dugdale of Crathorne, a former High Sheriff of Yorkshire, and sister of Thomas Dugdale, 1st Baron Crathorne.They had three children:He worked as Chairman of the National Mutual Life Assurance Society.He succeeded as the 20th Earl of Rothes on the death of his father in 1927.He served as a Representative Peer for Scotland until this system was abolished.The Earl died on 7 May 1975.The Rothes Chair in Preventive Ophthalmology was established at London University in his memory in 1977. [SEP] Knowledge 2: George Leslie, 15th Earl of Rothes
George William Evelyn Leslie, 15th Earl of Rothes (8 November 1809 – 10 March 1841) was the son of Henrietta Leslie, 14th Countess of Rothes and George Gwyther.He was christened on 14 December at Saint Mary-St Marylebone Road, St Marylebone, London, England.
Leslie succeeded his mother Henrietta Anne, to the title Earl of Rothes, in 1819.On 7 May 1831, he married Louisa Susannah Jane Anderson Morshead, daughter of Henry Anderson Morshead, and they had issue:

Answer: Norman Leslie, 19th Earl of Rothes