The following is an extract from "ThePeerage.com"

William Ponsonby, 1st Viscount Duncannon

b. 1659, d. 17 November 1724. He was buried at Fiddown, County Kilkenny, Ireland. He was created 1st Viscount Duncannon, of the fort of Duncannon, Co. Wexford  on 28 February 1723.

Brabazon Ponsonby, 1st Earl of Bessborough

b. 1679, d. 4 July 1758

Brabazon Ponsonby, 1st Earl of Bessborough|b. 1679\nd. 4 Jul 1758|p2715.htm#i27141|William Ponsonby, 1st Viscount Duncannon|b. 1659\nd. 17 Nov 1724|p3191.htm#i31901|Mary Moore|b. c 1662\nd. 26 May 1713|p3191.htm#i31904|Sir John Ponsonby|b. c 1608\nd. 1678|p3190.htm#i31896|Elizabeth Folliott|b. b 1622|p3190.htm#i31891|Hon. Randle Moore||p3191.htm#i31905|Lady Jane Brabazon||p13093.htm#i130925|

He succeeded to the title of 2nd Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 17 November 1724.

William Ponsonby, 2nd Earl of Bessborough

b. 1704, d. 11 March 1793

William Ponsonby, 2nd Earl of Bessborough|b. 1704\nd. 11 Mar 1793|p1288.htm#i12873|Brabazon Ponsonby, 1st Earl of Bessborough|b. 1679\nd. 4 Jul 1758|p2715.htm#i27141|Sarah Margetson|d. 21 May 1733|p2715.htm#i27142|William Ponsonby, 1st Viscount Duncannon|b. 1659\nd. 17 Nov 1724|p3191.htm#i31901|Mary Moore|b. c 1662\nd. 26 May 1713|p3191.htm#i31904|John Margetson|b. 1656/57|p2715.htm#i27143|Hon. Alice Caulfeild|b. c 1660\nd. 7 Oct 1731|p13093.htm#i130927|

He succeeded to the title of 3rd Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 4 July 1758.

Mrs Hervey recorded that "Lord Bessborough is here, who can never grow better or worse, or other than he is; it is incredible what nonsense he talks."

Frederick Ponsonby, 3rd Earl of Bessborough1

b. 24 January 1758, d. 3 February 1844

He succeeded to the title of 4th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 11 March 1793.
"He is a man of the most amiable and mild manners; without at all affecting the character of an orator, he is an excellent speaker, and much attended on. He takes a decided part against the Union."

John William Ponsonby, 4th Earl of Bessborough

b. 31 August 1781, d. 16 May 1847

He succeeded to the title of 5th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 3 February 1844. Greville writes that "no man ever quitted the world more surrounded by sympathy, approbation, respect an affection. He had a remarkably calm and unruffled temper, and very good sound sense... In his administration [of Ireland], adverse and unhappy as the times were, he displayed great industry, firmness, and knowledge of the circumstances and character of the Irish people, and he conciliated the goodwill of those to whom he had been, all his life, opposed."

John George Brabazon Ponsonby, 5th Earl of Bessborough

b. 14 October 1809, d. 28 January 1880

He succeeded to the title of 6th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 16 May 1847. He succeeded to the title of 2nd Baron Duncannon of Bessborough, Co. Kilkenny on 16 May 1847.

Frederick George Brabazon Ponsonby, 6th Earl of Bessborough

b. 11 September 1815, d. 11 March 1895

He succeeded to the title of 7th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 28 January 1880. He succeeded to the title of 3rd Baron Duncannon of Bessborough, Co. Kilkenny on 28 January 1880.

Reverend Walter William Brabazon Ponsonby, 7th Earl of Bessborough

b. 13 August 1821, d. 24 February 1906

He succeeded to the title of 4th Baron Duncannon of Bessborough, Co. Kilkenny on 11 March 1895. He succeeded to the title of 8th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 11 March 1895.

Edward Ponsonby, 8th Earl of Bessborough

b. 1 March 1851, d. 1 December 1920

He succeeded to the title of 5th Baron Duncannon of Bessborough, Co. Kilkenny on 24 February 1906. He succeeded to the title of 9th Viscount Duncannon, of the

fort of Duncannon, Co. Wexford on 24 February 1906. He succeeded to the title of 8th Earl of Bessborough on 24 February 1906.

Sir Vere Brabazon Ponsonby, 9th Earl of Bessborough

b. 27 October 1880, d. 10 March 1956

He succeeded to the title of 10th Viscount Duncannon, of the fort of Duncannon, co. Wexford [I., 1723] on 1 December 1920. He succeeded to the title of 6th Baron Duncannon of Bessborough, co. Kilkenny on 1 December 1920.

Frederick Edward Neuflize Ponsonby, 10th Earl of Bessborough

b. 29 March 1913, d. 5 December 1993

He succeeded to the title of 11th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 10 March 1956. He succeeded to the title of 7th Baron Duncannon of Bessborough, Co. Kilkenny on 10 March 1956. On his death, the Earldom of Bessborough [U.K.] became extinct.

Arthur Mountifort Longfield Ponsonby, 11th Earl of Bessborough

b. 11 December 1912, d. 5 April 2002

He succeeded to the title of 12th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 5 December 1993. He succeeded to the title of 8th Baron Duncannon of Bessborough, Co. Kilkenny on 5 December 1993.

Myles Fitzhugh Longfield Ponsonby, 12th Earl of Bessborough

b. 16 February 1941

He succeeded to the title of 13th Viscount Duncannon, of the fort of Duncannon, Co. Wexford on 5 April 2002. He succeeded to the title of 9th Baron Duncannon of Bessborough, Co. Kilkenny on 5 April 2002. He lived in 2003 at Stansted Park, Rowlands Castle, Hampshire, England.

Frederick Arthur William Ponsonby, Viscount Duncannon

b. 9 August 1974

He is the son of Myles Fitzhugh Longfield Ponsonby, 12th Earl of Bessborough and Alison Marjorie Storey. He married Emily Mott, daughter of Peter D. Mott.
Frederick Arthur William Ponsonby, Viscount Duncannon was educated at
Harrow School, Harrow on the Hill, London, England. He was educated at University of East Anglia, England. He was styled as Viscount Duncannon in 2002.

Hon. Eleanor Grace Ponsonby  b. 8 May 2006

Child of Frederick Arthur William Ponsonby, Viscount Duncannon, and Emily Mott