Philip Sidney, 2nd Baron De Lisle And Dudley

Philip Sidney, 2nd Baron De L'Isle and Dudley, was born on 28 January 1828 in London, England. He was the youngest child and only son of Philip Sidney, 1st Baron De L'Isle and Dudley, and Lady Sophia FitzClarence. His maternal grandfather was King William IV, through his illegitimate daughter Lady Sophia FitzClarence, who was born to the actress Dorothea Jordan. Sidney’s paternal grandfather was Sir John Shelley-Sidney, 1st Baronet. His paternal family line was related to poet Percy Bysshe Shelley, as his father was a first cousin of Shelley.

Sidney received his education at Eton College.

In his early career, Sidney served as an officer in the Royal Horse Guards, attaining the rank of Lieutenant. In March 1851, following his father's death, he inherited the titles of 3rd Shelley-Sidney baronet of Penshurst Place and 2nd Baron De L'Isle and Dudley of Penshurst, in Kent.

Sidney held the position of trustee of the National Portrait Gallery during his lifetime.

On 23 April 1850, Sidney married Mary Foulis, born in 1826, the only child of Sir William Foulis, 8th Baronet, and Mary Jane Ross. Upon his marriage, Sidney assumed the additional surname Foulis by Royal Warrant on 6 June 1850, as stipulated by his father-in-law’s will. He later relinquished this surname after her death in 1891.

Sidney and Mary Foulis had several children:

- Philip Sidney, 3rd Baron De L'Isle and Dudley (1853–1922), who married Lady Elizabeth Maria Vereker in 1902.

- Algernon Sidney, 4th Baron De L'Isle and Dudley (1854–1945), who participated in the Second Boer War and died unmarried.

- Hon. Henry Sidney (1858–1896), who died unmarried.

- William Sidney, 5th Baron De L'Isle and Dudley (1859–1945), married Winifred Agneta Yorke Bevan in 1905.

- Hon. Mary Sophia Sidney (d. 1903), who died unmarried.

Lady De L'Isle and Dudley died on 14 June 1891. Sidney remarried on 25 January 1893 to Emily Frances Ramsay, the daughter of William Fermor Ramsay of Croughton Park and Emily Susan Tredcroft. Sidney died in Westminster, London, on 17 February 1898, and was buried at Penshurst.

After his death, his widow married Sir Walter Stirling, 3rd Baronet, in February 1903. They divorced in 1909, and she died on 3 November 1926.

Through his youngest son William, Sidney was posthumously the grandfather of William Philip Sidney, who was created Viscount De L'Isle of Penshurst in the County of Kent on 12 January 1956.