The heavy-set face of Robert the Bruce, the father of Scottish independence, has re-emerged from the shadows nearly 700 years after his death.

Facial reconstruction experts at Liverpool John Moores University have released 3D digital images of the Scottish king, who led the Scots to victory against the English at Bannockburn in 1314, that show a privileged and muscular man, with large, broad features.

After a two-year project in collaboration with Glasgow University, they have found that King Robert, the descendant of Anglo-Norman nobles and Scottish aristocrats, had a powerful physique and ate an excellent diet during his 55 years.

The reconstructions are based on a cast held at the Hunterian museum of Robert the Bruce’s skull, which historians believe was recovered along with his skeleton in 1818-19 from Dunfermline Abbey and then reinterred. They said that in his youth he was a match for the superathletes of today.

Yet historians also believe that Robert had leprosy, which weakened him repeatedly during his later life. The cast of his skull shows apparent signs of leprosy, which seems to have disfigured his upper jaw and nose, so another set of digital images portray an older, more worn and marked face carrying its scars.

The skull used to reconstruct King Robert’s face. Photograph: Liverpool John Moores University

Until now depictions of the king, such as the striking monument at the Bannockburn battle memorial near Stirling and various Victorian engravings, have been based on speculation or the death mask on his tomb. There have also been modern facial reconstructions, which show some similarities to the latest one from Liverpool, but not with the same level of detail.

The joint project was launched after Dr Martin MacGregor, a Scottish history lecturer at Glasgow, watched the discovery of the remains of Richard III underneath a car park in Leicester in 2012.

MacGregor then approached Prof Caroline Wilkinson, a craniofacial identification expert and director of the LJMU’s Face Lab, who led the reconstruction of Richard’s face. There was some guesswork involved: they had no DNA samples to test and had to rely on statistics to speculate that he had brown eyes and hair.

The authenticity of this reconstruction is based heavily on faith in the historical record. Before reinterment, Bruce’s skeleton and skull were sealed in pitch, preventing the researchers from extracting usable DNA. The Hunterian, part of the University of Glasgow, possesses a toe bone thought to come from the grave, but it was too fragile to sample.

“We had hoped to try and obtain DNA from this and test it against a living descendant of Robert the Bruce, but the bone would probably have been destroyed in the process,” said MacGregor.

“I was aware of previous attempts to recreate the face of the skull linked to Robert the Bruce,” he added. “The case of Richard III revealed how far the technology had advanced. I saw an opportunity to apply the technology to the Hunterian skull: first to test the credibility of its connection to Bruce, and then to try to add to our knowledge of Scotland’s greatest king.”

Wilkinson said: “Using the skull cast, we could accurately establish the muscle formation from the positions of the skull bones to determine the shape and structure of the face.

“But what the reconstruction cannot show is the colour of his eyes, his skin tones and the colour of his hair. We produced two versions – one without leprosy and one with a mild representation of leprosy. He may have had leprosy, but if he did it is likely that it did not manifest strongly on his face, as this is not documented.”

Of Scotland’s historical figures, Robert the Bruce has the greatest resonance and casts the longest shadow. A fourth grandson of the 12th century Scots king David I through a female line, he believed he had a clear claim to the throne after John Balliol was taken into English custody before becoming Scotland’s king in exile in France.

After what was seen as an act of treachery, Bruce murdered John Comyn, his main rival for the throne, in a Dumfries church in February 1306, and then continued the campaign of resistance to English domination begun by William Wallace, the Scots leader portrayed in the Mel Gibson film Braveheart.

After his defeat by Edward I’s English forces at Falkirk, Wallace went on the run, before being captured in 1305. He was hung, drawn and quartered at Smithfield in London, the year before Bruce seized the throne. Bruce’s act was controversial, said MacGregor, since Balliol was still alive and some Scots disputed his claim.

“Edward I had just reduced Scotland to a ‘land’, just part of his empire. It ceased to be a kingdom; the kingship [of Scotland] was dead,” MacGregor said. “And Bruce, by resurrecting Scottish kingship, laid down the gauntlet [to the English].”

His victory over Edward II in 1314 secured Scotland as an independent kingdom. Yet unlike Wallace, and despite his historical dominance, Bruce never attracted the same cinematic attention.