Henry Mordaunt, 2nd Earl of Peterborough

Henry Mordaunt, 2nd Earl of Peterborough, KG, PC, FRS (15 November 1621 – 19 June 1697) was an English soldier, peer and courtier.

Styled Lord Mordaunt from 1628, he was the eldest son of John Mordaunt, 1st Earl of Peterborough and during the English Civil War, he commanded his ailing father's troop of horse on the side of the Roundheads from 1642. When his father died a year later, Mordaunt (now Earl of Peterborough) joined the Cavaliers and fought at the battles of Bristol, Gloucester and Newbury in 1643 and Cropredy Bridge and Lostwithiel in 1644. In about December 1644, he married Lady Penelope O'Brien (the only daughter of the 5th Earl of Thomond) and they had two daughters.

When Charles married Catherine of Braganza in 1661, he acquired Tangier as part of her dowry and Peterborough was sent there as its Governor. After fortifying the town's harbour, he returned home a few years later and captained the "Unicorn" at the Battle of Lowestoft in 1665 and later the "Prince" at the Battle of Solebay in 1672.

On James II's accession in 1685, Peterborough was made Groom of the Stole and a Knight of the Garter that year. When the King fled England three years later, Peterborough was caught trying to escape with him and was stripped of all his former offices and imprisoned in the Tower of London. He was unsuccessfully impeached for high treason and conversion to Roman Catholicism in 1689 and was released the next year. On his death in 1697, his earldom passed to his nephew, the Earl of Monmouth, and his barony (which was able to pass through the female line) passed to his daughter, the Duchess of Norfolk. Since she died childless, the barony returned to the earls of Peterborough until that title died out in 1814.