On 29 Nov 1774 Robert Blackwood 1st Baronet (age 80) died. His son John Blackwood 2nd Baronet (age 53) succeeded 2nd Baronet Blackwood of Killyleagh in County Down.

On 27 Feb 1799 John Blackwood 2nd Baronet (age 78) died. His son James Blackwood 2nd Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 43) succeeded 3rd Baronet Blackwood of Killyleagh in County Down.

On 08 Aug 1836 James Blackwood 2nd Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 81) died. His brother Hans Blackwood 3rd Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 78) succeeded 3rd Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 4th Baronet Blackwood of Killyleagh in County Down.

On 18 Nov 1839 Hans Blackwood 3rd Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 81) died. His son Price Blackwood 4th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 45) succeeded 4th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 5th Baronet Blackwood of Killyleagh in County Down.

On 21 Jul 1841 Price Blackwood 4th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down (age 47) died. His son Frederick Temple Hamilton-Temple-Blackwood 1st Marquess of Dufferin and Ava (age 15) succeeded 5th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 5th Baronet Blackwood of Killyleagh in County Down.

On 12 Feb 1902 Frederick Temple Hamilton-Temple-Blackwood 1st Marquess of Dufferin and Ava (age 75) died. His son Terence John Temple Hamilton-Temple-Blackwood 2nd Marquess of Dufferin and Ava (age 35) succeeded 2nd Marquess of Dufferin and Ava, 2nd Earl of Ava in County Down and Burma, 2nd Earl of Dufferin in County Down, 2nd Viscount Dufferin of Claneboye in County Down, 2nd Baron Claneboye of Claneboye in County Down, 6th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 6th Baronet Blackwood of Killyleagh in County Down.

On 11 Feb 1919 Terence John Temple Hamilton-Temple-Blackwood 2nd Marquess of Dufferin and Ava (age 52) died. His brother Frederick Temple Hamilton-Temple-Blackwood 3rd Marquess of Dufferin and Ava (age 43) succeeded 3rd Marquess of Dufferin and Ava, 3rd Earl of Ava in County Down and Burma, 3rd Earl of Dufferin in County Down, 3rd Viscount Dufferin of Claneboye in County Down, 3rd Baron Claneboye of Claneboye in County Down, 7th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 7th Baronet Blackwood of Killyleagh in County Down.

On 21 Jul 1930 Frederick Temple Hamilton-Temple-Blackwood 3rd Marquess of Dufferin and Ava (age 55) died. His son Basil Sheridan Hamilton-Temple-Blackwood 4th Marquess of Dufferin and Ava (age 21) succeeded 4th Marquess of Dufferin and Ava, 4th Earl of Ava in County Down and Burma, 4th Earl of Dufferin in County Down, 4th Viscount Dufferin of Claneboye in County Down, 4th Baron Claneboye of Claneboye in County Down, 8th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 8th Baronet Blackwood of Killyleagh in County Down. Maureen Constance Guinness Marchioness of Dufferin and Ava (age 23) by marriage Marchioness of Dufferin and Ava.

On 25 Mar 1945 Basil Sheridan Hamilton-Temple-Blackwood 4th Marquess of Dufferin and Ava (age 35) was killed in action. Lord Dufferin was serving with the Indian Field Broadcasting Unit on when he was filmed demanding the surrender of Japanese troops who were sheltered in a tunnel; the film captured Lord Dufferin's death when a Japanese mortar shell landed on the unit. His son Sheriden Frederick Terence Hamilton-Temple-Blackwood 5th Marquess of Dufferin and Ava (age 6) succeeded 5th Marquess of Dufferin and Ava, 5th Earl of Ava in County Down and Burma, 5th Earl of Dufferin in County Down, 5th Viscount Dufferin of Claneboye in County Down, 5th Baron Claneboye of Claneboye in County Down, 9th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down, 9th Baronet Blackwood of Killyleagh in County Down. Maureen Constance Guinness Marchioness of Dufferin and Ava (age 38) by marriage Marchioness of Dufferin and Ava.

On 29 May 1988 Sheriden Frederick Terence Hamilton-Temple-Blackwood 5th Marquess of Dufferin and Ava (age 49) died. Marquess of Dufferin and Ava, Earl of Ava in County Down and Burma, Earl of Dufferin in County Down, Viscount Dufferin of Claneboye in County Down, Baron Claneboye of Claneboye in County Down, Baronet Blackwood of Killyleagh in County Down extinct. His fourth cousin once removed Francis George Blackwood 10th Baron Dufferin and Clandeboye (age 72) succeeded 10th Baron Dufferin and Claneboye of Ballyleidy and Killyleagh in County Down.