There's no way to know just from 'Henry Henry novel' whether he is the protagonist. It could be that he is just a minor character or part of a sub - plot.
I'm not sure which specific 'Henry Henry' in a novel you are referring to. There could be many characters named Henry in various novels. Maybe it's a relatively unknown or self - published work. Without more context, it's difficult to determine who this 'Henry Henry' is.
We don't really know who Mr Barnes was just from the title. He could be an ordinary person who found himself in an extraordinary situation. Maybe he was a local businessman, a teacher, or just a regular guy in the neighborhood.
Julian Barnes' novels often have a strong focus on human nature. For example, in 'The Sense of an Ending', we see how the main character's self - perception and understanding of his relationships are deeply intertwined with his sense of self. His works also tend to be very cerebral, making the reader think about complex ideas like truth and memory.
Henry in the 'Haunted by Henry' true story could be a historical figure. He could have been a soldier who died in a battle near a certain place and now haunts it. Or he could be a local hermit who had a strange reputation during his life and after his death, people started experiencing strange things and attributed them to his haunting. Without more details, it's difficult to determine exactly who Henry is, but he is clearly the central figure in this supposed true haunting story.
In 'the john henry story', John Henry was a heroic figure. He was a railroad worker who was known for his amazing physical strength and his unyielding spirit. He became a symbol of human resistance against the rise of machinery in the workplace.
In the 'Henry Sugar True Story', Henry Sugar is presumably the protagonist. He could be from any walk of life. He might be a working - class man who had a series of unexpected events occur to him. It's possible that he had a great passion for something, like art or music, and his story could be about how this passion led him on different paths in his life. Or he could be a bit of an enigma, with the story gradually revealing more about who he really is as it progresses.
Since I don't know the specific 'Henry Sugar real story', I can't say exactly who he is. He could be an ordinary person with an extraordinary story, or perhaps a fictional character based on a real - life prototype.