Pembroke was the eldest son of Sidney Herbert, 1st Baron Herbert of Lea, only son of George Augustus Herbert, 11th Earl of Pembroke, by his second wife Catherine (née Countess Woronzow). His mother was Elizabeth Herbert, Baroness Herbert of Lea, daughter of Lieutenant-General Charles Ashe A"Court.
He was Under-Secretary of State for War under Benjamin Disraeli between 1874 and 1875. Pembroke served as Under-Secretary of State for War from 1874 to 1875 in the second Conservative administration of Benjamin Disraeli. He took a leading part in the volunteer movement, holding a commission for upwards of twenty years, and commanding the South Wiltshire battalion until within a few months of his death.
He believed firmly in the advantage of technical instruction, and gave practical proof thereof by building and endowing the Pembroke technical school near Dublin.
Lord Pembroke was a good sportsman, having been first a master of harriers for many years, and later of foxhounds. But a bad fall put an end to his hunting, and latterly he spent much of his time afloat, yachting and boat-sailing.
Lord Pembroke married Lady Gertrude Frances, daughter of Henry Chetwynd-Talbot, 18th Earl of Shrewsbury, in 1874. The Countess of Pembroke died in September 1906, aged 66.
Lord Pembroke never accepted office again, and rarely spoke in the House of Lords, but he continued to take a keen interest in public affairs, both imperial and domestic, and communicated his views, through various periodicals and by speeches in the country, upon Ireland, the land question, imperial defence, and the navy.
