Archibald Philip Primrose, 5th Earl of Rosebery, 1st Earl of Midlothian, KG, PC was a British Liberal statesman and Prime Minister. Between the death of his father, in 1851, and the death of his grandfather, the 4th Earl, in 1868, he was known by the courtesy title of Lord Dalmeny.
Rosebery was a Liberal Imperialist who favoured strong national defence and imperialism abroad and social reform at home, while being solidly anti-socialist. His parents were Scottish and his earldom title was part of the peerage of Scotland. Rosebery married Hannah de Rothschild, the heiress of Mayer Amschel de Rothschild.