The death of England's King Richard III, the last of the country's kings to be killed in a battle, was a gruesome one, a forensic examination of the monarch's remains has revealed.

Computer scans of the king's skeletal remains, discovered beneath a parking lot in Leicester in 2012, show he suffered at least 11 wounds, three of which would have caused a quick death, researchers say.

During the Battle of Bosworth Field in 1485, the king suffered two wounds to the skull and one to his pelvis that would have been fatal even by themselves, University of Leicester researchers reported in the journal The Lancet.

"Richard's injuries represent a sustained attack or an attack by several assailants with weapons from the later medieval period," says study author Sarah Hainsworth. "The wounds to the skull suggest that he was not wearing a helmet, and the absence of defensive wounds on his arms and hands indicate that he was otherwise still armored at the time of his death."

The head wounds suggest Richard either took his helmet off during the battle or lost it when he was dismounted from his horse, the researchers say.

The injuries to the skeleton suggest the attack on Richard III involved swords, daggers and a weapon employed to pull mounted riders down off their horses, consisting of a long metal pole topped with a hook and an axe, the researchers say.

One account of the battle with the forces of Henry Tudor, who after the battle claimed the throne as Henry VII, said Richard was surrounded when his horse became mired in marshy ground.

"Medieval battlefields saw an array of weapons used, from swords, battle hammers, maces, arrows and even early firearms," Robert Woosnam-Savage of the Royal Armories Museum of Leeds, told the BBC.

Richard likely managed to get close to Henry before his horse either became mired in the marsh or possibly was killed from beneath him. At that point foot soldiers would have moved in for the kill, Woosnam-Savage said.

One outcome of the examination of Richard' skeleton was the confirmation that, although he suffered from scoliosis -- a curvature of his spine -- he was not the hunchback portrayed by Shakespeare and perpetuated over the centuries that followed.

Still, the researchers say, the forensic examination has showed without doubt that combat in the age of edged weapons was a truly nasty affair.

"Medieval battle was bloody and brutal," Hainsworth says. "Richard was probably in quite a lot of pain at the end."