ˌɔn twˈɛnti sˈɛvən noʊvˈɛmbɚ wˈʌn θˈaʊzənd sˈɛvənhˈʌndɹɪd ˈeɪɾi, dˈʌŋkænən mˈæɹid ðɪ ɪntˈɛlɪdʒənt ænd kˈaɪnd lˈeɪdi hˌɛnɹɪˈɛɾə spˈɛnsɚ, sˈɛkənd dˈɔːɾɚɹ ʌv dʒˈɑːn spˈɛnsɚ, fˈɜːst ˈɜːl spˈɛnsɚ.
On 27 November 1780, Duncannon married the intelligent and kind Lady Henrietta Spencer, second daughter of John Spencer, 1st Earl Spencer.