On 20 Aug 1825 William Waldegrave 1st Baron Radstock (age 72) died. His son Vice Admiral Granville Waldegrave 2nd Baron Radstock (age 38) succeeded 2nd Baron Radstock of Castletown in the Queen's County.

On 11 May 1857 Vice Admiral Granville Waldegrave 2nd Baron Radstock (age 70) died. His son Granville Waldegrave 3rd Baron Radstock (age 24) succeeded 3rd Baron Radstock of Castletown in the Queen's County.

On 08 Dec 1913 Granville Waldegrave 3rd Baron Radstock (age 80) died in Paris [Map]. His son Granville Waldegrave 4th Baron Radstock (age 54) succeeded 4th Baron Radstock of Castletown in the Queen's County.

On 02 Apr 1937 Granville Waldegrave 4th Baron Radstock (age 77) died unmarried. His brother Montague Waldegrave 5th Baron Radstock (age 69) succeeded 5th Baron Radstock of Castletown in the Queen's County.

On 17 Sep 1953 Montague Waldegrave 5th Baron Radstock (age 86) died without male issue. Baron Radstock of Castletown in the Queen's County extinct.