George (Plantagenet), Duke of Clarence (October 21, 1449 - February 18, 1478) was the third son of Richard, Duke of York and Cecily Neville, and the brother of King Edward IV of England. He played an important role in the dynastic struggle known as the Wars of the Roses, but is better remembered as the character in William Shakespeare's play Richard III who was drowned in a vat of Malmsey wine.

George was born on October 21, 1449 in Dublin, at a time when his father, having assumed the name Plantagenet to emphasize his descent from King Henry II of England, was beginning to challenge King Henry VI of England for the crown. Following his father's death and the accession of his elder brother, Edward, to the throne, George was created Duke of Clarence in 1461. On July 11, 1469, he married Isabel Neville, elder daughter of Richard Neville, Earl of Warwick ("Warwick the Kingmaker"). Through her, Clarence would himself inherit the title, Earl of Warwick, following her father's death.

Clarence had actively supported his elder brother's claim to the throne, but, following his marriage, he began to play a dangerous game. When his father-in-law, the Earl of Warwick, became discontented and jealous, and deserted Edward to ally himself with Margaret of Anjou, consort of the deposed King Henry, Clarence joined him in France, taking his pregnant wife, Isabel. She gave birth to their first child (who died shortly afterwards) on April 16, 1470, in a ship off Calais. After a short time, Clarence realised that his loyalty to his father-in-law was misplaced, for Warwick proceeded to marry his younger daughter, Anne, to the Prince of Wales, King Henry's heir, and it became evident that he was placing his own interests before those of Clarence and Isabel. There now seemed little chance that he intended to place Clarence on the throne instead of his elder brother; so Clarence changed sides.

Warwick's efforts to return Henry VI to the throne having failed, and Warwick himself having been killed in battle, George was restored to the royal favour, but now saw his main rival as his younger brother, Richard, Duke of Gloucester, who had married the widowed Anne Neville. The Neville sisters were heiresses to their mother's considerable estates, and their husbands vied with one another for pride of place, with Richard eventually winning out. Clarence, who had made the mistake of plotting against his brother Edward IV, was imprisoned in the Tower of London and put on trial for treason. Following his conviction, he was "privately executed" at the Tower on February 18, 1478, and the tradition grew up that he had been drowned in a butt of Malmsey wine. The tradition may have originated in a joke, based on his reputation as a heavy drinker. However, a butt was equal to two hogsheads - 105 imperial gallons - easily enough to drown in. In fact, it has been speculated that the fumes from an open butt alone would be sufficient to render a man unconscious. Also, the excavation of a body believed to be that of Clarence, showed no damage to the neck region that would indicate a beheading, the normal method of execution for those of noble birth in the middle ages.

Clarence's wife, Isabel, had died in 1476, and they are buried together at Tewkesbury Abbey in Gloucestershire (traditional). Their surviving children, Margaret and Edward, were cared for by their aunt, Anne Neville, until she died in 1485, when Edward was 10 years old.