What was the name of Richard III's son who died young?

Richard III’s son who died young was Edward of Middleham, Prince of Wales.

Edward was the only legitimate child of Richard, Duke of Gloucester, and Anne Neville. He was born at Middleham Castle in Yorkshire, probably between 1474 and 1476, although the exact year remains uncertain. Middleham was an important stronghold of Richard and Anne and became closely associated with their northern power base.

Richard became king in 1483, and Edward was formally created Prince of Wales later that year in a ceremony at York Minster. The boy was described as sickly and did not attend his parents’ coronation, probably because of illness. He died suddenly on 9 April 1484 at Middleham, aged somewhere between seven and ten.

Edward’s death left Richard without a legitimate son and created a serious succession problem. The exact cause of death is unknown; later suggestions such as tuberculosis are speculative. Edward of Lancaster and Edward of Westminster belonged to the Lancastrian line, while Edward of Woodstock was the Black Prince, a much earlier Plantagenet prince.