Egil Skalla-Grimsson, who died in about 990AD and was so physically menacing and irritable that he became the subject of an Icelandic saga, may have suffered from Paget's disease, when the bones and skull become grossly deformed.
Part of the legend of Egil is that his skull was dug up 150 years after his death and was so thick it could withstand the hardest blow from an axe. He also complained of cold feet, a sign of poor circulation.
A reappraisal of Egil's exploits by Jesse Byock, professor of Old Norse and Scandinavian studies at the University of California, Los Angeles, found the warrior was the victim of the progressive bone disease.
``What set Egil apart was more than simply a small, personal peculiarity,'' Professor Byock says in the current issue of Scientific American.
``Through prose and verse, the saga tells us that Egil became deaf, often lost his balance, went blind, suffered from chronically cold feet, endured headaches and experienced bouts of lethargy.''
Egil has puzzled scholars because he displayed all the attributes of a thug yet still managed to write good poetry and verse. ``Rather than attributing conflicting aspects of Egil's personality to artistic hyperbole, I believe the descriptions stem from the progress of Paget's disease,'' Professor Byock says.
One account of Egil records him ``with broad forehead and large eyebrows, a nose that was not long but enormously thick, and lips that, seen through his beard, were both wide and long . . . He was thick-necked and broad-shouldered and, more so than othermen, hard-looking and fierce when angry''.
His skull was ridged all over like a scallop shell and was so thick it survived the hardest blow from a heavy axe when Egil's bones were exhumed in Iceland 150 years after his death.
Professor Byock says that no matter how realistic this description, it was evident that no normal skull could survive such treatment and so the story of Egil's skull was thought to be a purely literary device that was ``intended to magnify his heroic qualities''.
Paget's disease, however, causes exactly this type of ridge growth on the skull, which becomes thickened and deformed, often affecting the sight and hearing, but leaving the brain unaffected.
Egil's notorious cold feet were probably the result of blood being diverted from the extremities to support the rapid bone growth elsewhere in the body, Professor Byock says.