Ian Archibald James Duff1 
He was educated at Aldenham School, Elstree, Hertfordshire, EnglandG.2 He fought in the First World War.2 He gained the rank of Captain in the Dorset Regiment.3 He was awarded the Military Cross (M.C.)3 He gained the rank of in the Royal Air Force.3 He graduated from Trinity Hall, Cambridge University, Cambridge, Cambridgeshire, EnglandG, in 1921 with a Bachelor of Arts (B.A.)2
Children of Ian Archibald James Duff and Kathleen Frances Chinnery-Haldane
- Dr. Sheila Mary Helen Duff1 b. 29 Dec 1918, d. 8 Sep 1955
- Patrick Charles Duff1 b. 4 Apr 1920
- Alexander Ian Duff1 b. 19 Jul 1922, d. c 1957
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
- [S37] BP2003 volume 1, page 1205. See link for full details for this source. Hereinafter cited as. [S37]
- [S37] BP2003. [S37]
Kathleen Frances Chinnery-Haldane1 
From 30 August 1916, her married name became Duff.3
Children of Kathleen Frances Chinnery-Haldane and Ian Archibald James Duff
- Dr. Sheila Mary Helen Duff3 b. 29 Dec 1918, d. 8 Sep 1955
- Patrick Charles Duff3 b. 4 Apr 1920
- Alexander Ian Duff3 b. 19 Jul 1922, d. c 1957
- [S37] BP2003 volume 2, page 1724. See link for full details for this source. Hereinafter cited as. [S37]
- [S37] BP2003. [S37]
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Dr. Sheila Mary Helen Duff1 
Her married name became Hugh-Musgrove.
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Patrick Charles Duff1
He lived in 2003 at Lower Post, Alaska Highway, British Columbia, CanadaG.2
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
- [S37] BP2003 volume 1, page 1205. See link for full details for this source. Hereinafter cited as. [S37]
Alexander Ian Duff1 
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Colin Guthrie Duff1
He was educated at Aldenham School, Elstree, Hertfordshire, EnglandG.2
Child of Colin Guthrie Duff and Clare Mabel Delahay
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
- [S37] BP2003 volume 1, page 1205. See link for full details for this source. Hereinafter cited as. [S37]
Clare Mabel Delahay1
Her married name became Duff.3
Child of Clare Mabel Delahay and Colin Guthrie Duff
- [S37] BP2003 volume 1, page 1205. See link for full details for this source. Hereinafter cited as. [S37]
- [S37] BP2003. [S37]
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Margaret Duff1
Her married name became Pye.1
Child of Margaret Duff and Terrence Pye
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Terrence Pye1
Child of Terrence Pye and Margaret Duff
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”
Colin John Pye1
- [S1438] Sir William, Bt. Arbuthnot, “re: Arbuthnot and Duff Families,” e-mail message to British and European Nobility Register, 29 August 2005 and later. Hereinafter cited as “re: Arbuthnot and Duff Families.”