On 15 Oct 1756 William Grimston 1st Viscount Grimston (age 71) died. His son James Grimston 2nd Viscount Grimston (age 45) succeeded 2nd Viscount Grimston, 6th Baronet Grimston of Little Waltham in Essex.

On 15 Dec 1773 James Grimston 2nd Viscount Grimston (age 62) died. His son James Grimston 3rd Viscount Grimston (age 26) succeeded 3rd Viscount Grimston, 7th Baronet Grimston of Little Waltham in Essex.

On 30 Dec 1808 James Grimston 3rd Viscount Grimston (age 61) died. His son James Walter Grimston 1st Earl Verulam (age 33) succeeded 4th Viscount Grimston, 8th Baronet Grimston of Little Waltham in Essex.

On 17 Nov 1845 James Walter Grimston 1st Earl Verulam (age 70) died. His son James Walter Grimston 2nd Earl Verulam (age 36) succeeded 2nd Earl Verulam, 2nd Viscount Grimston, 5th Viscount Grimston, 2nd 9th Baronet Grimston of Little Waltham in Essex. Elizabeth Joanna Weyland Countess Verulam (age 20) by marriage Countess Verulam.

On 27 Jul 1895 James Walter Grimston 2nd Earl Verulam (age 86) died. His son James Walter Grimston 3rd Earl Verulam (age 43) succeeded 3rd Earl Verulam, 3rd Viscount Grimston, 6th Viscount Grimston, 10th Baronet Grimston of Little Waltham in Essex. Margaret Francis Graham Countess Verulam (age 41) by marriage Countess Verulam.

On 11 Nov 1924 James Walter Grimston 3rd Earl Verulam (age 72) died. His son James Grimston 4th Earl of Verulam (age 44) succeeded 4th Earl Verulam, 4th Viscount Grimston, 7th Viscount Grimston, 11th Baronet Grimston of Little Waltham in Essex. Violet Constance Maitland Brabazon Countess Verulam (age 38) by marriage Countess Verulam.

On 29 Nov 1949 James Grimston 4th Earl of Verulam (age 69) died. His son James Grimston 5th Earl of Verulam (age 39) succeeded 5th Earl Verulam, 5th Viscount Grimston, 8th Viscount Grimston, 12th Baronet Grimston of Little Waltham in Essex.

On 13 Oct 1960 James Grimston 5th Earl of Verulam (age 50) died. His brother John Grimston 6th Earl of Verulam (age 48) succeeded 6th Earl Verulam, 6th Viscount Grimston, 9th Viscount Grimston, 13th Baronet Grimston of Little Waltham in Essex.

On 15 Apr 1973 John Grimston 6th Earl of Verulam (age 60) died. His son John Grimston 7th Earl of Verulam (age 21) succeeded 7th Earl Verulam, 7th Viscount Grimston, 10th Viscount Grimston, 14th Baronet Grimston of Little Waltham in Essex.