Sir Henry St John-Mildmay, 4th Baronet

Sir Henry St John Carew St John-Mildmay, 4th Baronet, was born on 15 April 1787 and died on 17 January 1848. He was associated with Dogmersfield Park in Hampshire. His father was Sir Henry St John-Mildmay, 3rd Baronet, and his mother was Jane Mildmay, daughter and co-heiress of Carew Mildmay of Shawford House, Hampshire.

St John-Mildmay received his education at Winchester School from 1798 to 1802. He later attended Christ Church, Oxford, from which he graduated in 1805.

In his political career, he served as a Member of Parliament for Winchester from 1807 to 1818. He also held the position of Mayor of Winchester in 1808. He inherited the baronetcy on 11 November 1808 following the death of his father.

He married Charlotte Bouverie on 7 August 1809. Charlotte was the daughter of Hon. Bartholomew Bouverie and Mary Wyndham Arundell. The marriage produced one son before Charlotte's death: Sir Henry Bouverie Paulet, born in 1810. Sir Henry Bouverie Paulet married Hon. Helena Shaw-Lefevre, daughter of Charles Shaw-Lefevre, 1st Viscount Eversley, in 1851. Charlotte Bouverie died shortly after childbirth.

In 1815, five years after his first wife’s death, St John-Mildmay eloped with Harriet Bouverie, his late wife’s sister and the widow of Archibald Primrose, 4th Earl of Rosebery, while in Stuttgart, Württemberg. Harriet was known as the Countess of Rosebery. Before Harriet eventually left him, they had three sons:

- Edmund Henry St John-Mildmay (1815–1905), who married Louisa Josephine Saunders, the former wife of Sir Henry de Hoghton, 9th Baronet.

- Horace Osborne St John-Mildmay (1817–1866), an officer in the 5th Austrian Hussars, who married Jane Dombach in 1844.

- Augustus Fitzwalter St John-Mildmay, an officer in the 7th Austrian Hussars, who died unmarried in 1839.

After Harriet’s departure, St John-Mildmay married his cousin Augusta Jane St John-Mildmay, daughter of the Ven. Carew Antony St John-Mildmay.

Financial difficulties troubled him during his lifetime. On 17 January 1848, he died by shooting himself, an act attributed to his financial problems.