He succeeded to the title in 1799, and in 1805 married Emily Mary Lamb, daughter of Sir Peniston Lamb, first Viscount Melbourne.

REFERENCES TO Peter Leopold Louis Francis Nassau Cowper, fifth earl Cowper:

Duchess of Devonshire to Lady Melbourne, [17 December 1801] in In Whig Society 1775-1818: Compiled from the hitherto unpublished Correspondence of Elizabeth, Viscountess Melbourne, and Emily Lamb, Countess Cowper, afterwards Viscountess Palmerston (London: Hodder and Stoughton LTD., 1921)

Eleanor Creevey to Elizabeth Ord, 25 August 1806 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Elizabeth Inchbald to Samuel Rogers, 16 March 1808 in Samuel Rogers and his Contemporaries 2 Vols (London: Smith, Elder & Co., 1889)

Lord Holland to William Godwin, 11 May 1808 in William Godwin: his Friends and Contemporaries (London: Henry S. King & Co., 1876)

Henry Luttrell to Samuel Rogers, 20 September [1809] in Samuel Rogers and his Contemporaries 2 Vols (London: Smith, Elder & Co., 1889)

Lord Byron to William Bankes, 28 September 1812 in Letters and Journals of Lord Byron 2 Vols (London: John Murray, 1830)

Lord Byron to Samuel Rogers, 27 June 1814 in Letters and Journals of Lord Byron 2 Vols (London: John Murray, 1830)

Lord John Townshend to Samuel Rogers, 13 August 1816 in Samuel Rogers and his Contemporaries 2 Vols (London: Smith, Elder & Co., 1889)

Henry Brougham to Thomas Creevey, 14 November 1816 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Lord Melbourne to Lady Melbourne [1818?] in In Whig Society 1775-1818: Compiled from the hitherto unpublished Correspondence of Elizabeth, Viscountess Melbourne, and Emily Lamb, Countess Cowper, afterwards Viscountess Palmerston (London: Hodder and Stoughton LTD., 1921)

Thomas Creevey to Elizabeth Ord, 25 August 1820 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 6 September 1820 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 8 September 1820 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 6 November 1820 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 29 January 1821 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 18 June 1822 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Lord Byron to the Earl of Blessington, 5 April 1823 in Letters and Journals of Lord Byron 2 Vols (London: John Murray, 1830)

Lady Caroline Lamb to Lady Morgan, 27 May 1823 in Lady Morgan’s Memoirs: Autobiography, Diaries and Correspondence. Second Edition, Revised 2 vols (London: Wm. H. Allen & Co., 1863)

Thomas Creevey to Elizabeth Ord, 25 June 1824 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Henry Luttrell to Samuel Rogers, 8 November 1824 in Samuel Rogers and his Contemporaries 2 Vols (London: Smith, Elder & Co., 1889)

Thomas Creevey to Elizabeth Ord, 6 June 1825 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 23 September 1827 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 26 August 1828 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 28 March 1831 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 9 May 1831 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Thomas Creevey to Elizabeth Ord, 13 February 1832 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)