She had landed at Weymouth on the very same day as the battle of Barnet and was trying to make her way to Wales by crossing the River Severn. The nearest crossing was at the city of Gloucester, but after receiving a message from Edward IV, the Governor Sir Richard Beauchamp refused to open the city gates to her and her forces. This made them embark on a continued march for another 16 kilometres and they eventually made camp outside Tewkesbury where the Yorkist army finally caught up with them.
As the day broke, Margaret of Anjou sought shelter at a religious house. The Lancastrian army numbered 6 000 soldiers and the Yorkist 5 000. Edward IV:s vanguard was led by his brother Richard, Duke of Gloucester. As it became obvious that the Lancastrians wasn´t able to put up the resistance required, both soldiers and commanders began to flee, many being cut down from behind as they ran, while knights and nobles sought sanctuary at Tewkesbury Abbey.
It was a decisive victory which effectively eradicated any hope the Lancastrians had held of recovering the throne for Henry VI and not least for the Prince of Wales; Edward of Westminster, not least because when the battle was over, the latter was dead.
It is not absolutely clear at which point during the battle the Prince of Wales was killed, some sources claim he was killed in the battle itself, others that he tried to run and was killed during the flight, others still that he was caught and brought to Edward IV, only to be executed.
After the battle, Edward decided to break sanctuary, dragging the hiding men out and executing the commanders, one of which was Edmund Beaufort, and with him the House of Beaufort was basically exterminated, with the exception of Margaret Beaufort and her son Henry. Jasper Tudor, Henry´s uncle and guardian had been present at Tewkesbury but fled to Wales, bringing young Henry with him.
A few days after the battle, Margaret of Anjou surrendered to Edward IV, most likely distraught by the death of her son and in effect, the death of the House of Lancaster. She was brought to London as a prisoner of war and imprisoned in the Tower where her husband Henry VI was already held. The same night Henry VI died in the Tower, most likely murdered either on the orders of Edward himself or his brother Richard of Gloucester.
Sources: Bosworth Field & the Wars of the Roses – A.L. Rowse
The Wars of the Roses – Alison Weir
The Road to Bosworth Field – Trevor Royle
Images: Tewkesbury Abbey Interior – David Merrett
The murder of Edward of Westminster – James William Edmund Doyle, 1822-2892
(Engraver: Edmund Evans, 1826-1905)