Dorothy Sidney, the niece of the poet, Sir Philip, and the sister of the patriot Algernon, is yet more distinguished by the attachment, real or imaginary, of another Petrarch, the poet Waller; to whom, under the little-euphonous name of Saccarissa, she served as a Laura.

She was born in 1620, and married, in 1639, Henry Spencer, Lord Spencer of Wormleighton, afterwards Earl of Sunderland. He was killed at the battle of Edgehill. leaving her a young widow of twenty-three, with a son and two daughters. She remained ten years unmarried, and then became the wife of Robert Smythe, Esq., the eldest son of Sir John Smythe, of Bounds, in Kent.