Richard III, whose bones were recently found, was indeed suffering from scoliosis (he was a hunchback).
Ancient Standard discusses, and says it was idiopathic scoliosis.
Idiopathic scoliosis is more common in girls (and alas is common).
But it is less common in boys.
Many boys with scoliosis are born with a "hemivertebrae" which causes the problem, but the skeleten suggests his vertebrae/back bones were normal (not severely deformed). Cerebral palsy and some musculoskeletal problems can also cause this to happen.
Or did it develope from an injury, or from polio (and if so he would have weak legs) or ideopathic (which develops at puberty, during the growth spurt.).
I'll probably google about it later and put it on my medical blog.
Router is still out, and Joy's computer is out since Ruby spilled a soda on the keyboard, so I'm sharing the office computer with two people.