On 28 Dec 1719 William Fitzwilliam 1st Earl Fitzwilliam (age 76) died. His son John Fitzwilliam 2nd Earl Fitzwilliam (age 34) succeeded 2nd Earl Fitzwilliam, 4th Baron Fitzwilliam of Liffer in Donegal.

On 28 Aug 1728 John Fitzwilliam 2nd Earl Fitzwilliam (age 43) died. His son William Fitzwilliam 1st and 3rd Earl Fitzwilliam (age 8) succeeded 3rd Earl Fitzwilliam5th Baron Fitzwilliam of Liffer in Donegal.

On 10 Aug 1756 William Fitzwilliam 1st and 3rd Earl Fitzwilliam (age 36) died. His son William Fitzwilliam 4th and 2nd Earl Fitzwilliam (age 8) succeeded 4th Earl Fitzwilliam, 2nd Earl Fitzwilliam, 6th Baron Fitzwilliam of Liffer in Donegal. Charlotte Ponsonby Countess Fitzwilliam by marriage Countess Fitzwilliam.

On 08 Feb 1833 William Fitzwilliam 4th and 2nd Earl Fitzwilliam (age 84) died. His son Charles Wentworth-Fitzwilliam 5th and 3rd Earl Fitzwilliam (age 46) succeeded 5th Earl Fitzwilliam, 3rd Earl Fitzwilliam, 7th Baron Fitzwilliam of Liffer in Donegal.

On 04 Oct 1857 Charles Wentworth-Fitzwilliam 5th and 3rd Earl Fitzwilliam (age 71) died. His son William Thomas Wentworth-Fitzwilliam 6th and 4th Earl Fitzwilliam (age 41) succeeded 6th Earl Fitzwilliam, 4th Earl Fitzwilliam, 8th Baron Fitzwilliam of Liffer in Donegal. Frances Harriet Douglas Countess Fitzwilliam by marriage Countess Fitzwilliam.

On 20 Feb 1902 William Thomas Wentworth-Fitzwilliam 6th and 4th Earl Fitzwilliam (age 86) died. His grandson William Charles de Meuron "Billy" Wentworth-Fitzwilliam 7th and 5th Earl Fitzwilliam (age 29) succeeded 7th Earl Fitzwilliam, 5th Earl Fitzwilliam, 9th Baron Fitzwilliam of Liffer in Donegal. Maud Frederica Elizabeth Dundas Countess Fitzwilliam (age 24) by marriage Countess Fitzwilliam.

On 15 Feb 1943 William Charles de Meuron "Billy" Wentworth-Fitzwilliam 7th and 5th Earl Fitzwilliam (age 70) died at Wentworth Woodhouse. His son William Henry Lawrence Peter Wentworth-Fitzwilliam 8th and 6th Earl Fitzwilliam (age 32) succeeded 8th Earl Fitzwilliam, 6th Earl Fitzwilliam, 10th Baron Fitzwilliam of Liffer in Donegal.

On 13 May 1948 Kathleen "Kick" Kennedy (age 28) and William Henry Lawrence Peter Wentworth-Fitzwilliam 8th and 6th Earl Fitzwilliam (age 37) died in a plane crash at the Plateau du Coiron, Saint-Bauzile during the course of their journey from Paris [Map]. His first cousin once removed Eric Spencer Wentworth-Fitzwilliam 9th and 7th Earl Fitzwilliam (age 64) succeeded 9th Earl Fitzwilliam, 7th Earl Fitzwilliam, 11th Baron Fitzwilliam of Liffer in Donegal. His wealth, estimated at 45 million pounds, including half of the Wentworth Woodhouse estate, the Coolattin estate in County Wicklow, Ireland, and a large part of the Fitzwilliam art collection went to his daughter Ann Juliet Dorothea Maud Wentworth-Fitzwilliam Marchioness Bristol (age 13).

On 03 Apr 1952 Eric Spencer Wentworth-Fitzwilliam 9th and 7th Earl Fitzwilliam (age 68) died. His second cousin William Thomas Wentworth-Fitzwilliam 10th and 8th Earl Fitzwilliam (age 47) succeeded 10th Earl Fitzwilliam, 8th Earl Fitzwilliam, 12th Baron Fitzwilliam of Liffer in Donegal.

In 1979 William Thomas Wentworth-Fitzwilliam 10th and 8th Earl Fitzwilliam (age 74) died. Earl Fitzwilliam, Earl Fitzwilliam and Baron Fitzwilliam of Liffer in Donegal extinct.