He was born at Highclere Castle, Hampshire and he died at the British Embassy, Rome. Herbert was the third son of Henry Herbert, 4th Earl of Carnarvon, the full brother of the writer and politician Aubrey Herbert and the half-brother of George Herbert, 5th Earl of Carnarvon, who financed the excavation of Tutankhamun"s tomb. He married Mary Elizabeth Willard, daughter of Joseph East. Willard, the United States ambassador to Spain, in 1921 and had three children.
His wife"s older sister married Kermit Roosevelt, son of the former United States president Theodore.