In the end I decided to take the first volume of Röhl's Wilhelm II biography with me on my trip, and so far I've been rereading the chapters I got through the first time around. Mostly it's been about Wilhelm's difficult birth and mid-19th century's medicine's best efforts to treat his withered left arm, most of which read more like a mix of malicious torture and superstitious quackery (e.g. the insertion of the infant Wilhelm's arm "in a freshly slaughtered hare" for half an hour twice weekly) than an effective rehabilitation regimen.
As I read Röhl's description, I found myself wondering about the lengths the court went to in their efforts to restore Wilhelm's arm. It all seems less an exercise in compassion for the person than a need to ensure that the future occupant of the throne be as perfect as the kingdom he ruled imagined itself. Perhaps nothing less can be expected from the political culture of the time, but I can't help but think that more modern attitudes towards disability could have resulted in a less-traumatized and more emotionally secure individual.