Your relative may just have been unlucky with his dogs.
Alternately, either the dog was badly trained, or simply not trained.
In the nineteen sixties, it was still fairly common to hear people shouting at dogs or even slapping or booting them.
That kind of treatment will often make a dog aggressive.
Presumably, the dog felt threatened by the people whom he bit, otherwise he wouldn't have bitten them.
With such sparse information, I don't think anyone can tell you exactly what went wrong here.
Dogs are frightened quite often by people who are mentally afflicted, who drink or use drugs. If Bill had any of these problems that might be the answer.
Like humans, a dog can have mental afflictions. A Labrador we had when I was a child, developed a mental condition that made it necessary to have the dog put down.
Seems it’s now Harry’s uncle - the Earl of Spencer - having his turn at a “tell all” book.
Another silly little ABC game - shops we have loved and lost?
