Who is Vladimir de Pachmann from The Great Pianists and what is their importance?

Vladimir de Pachmann was a little man acknowledged as greatest expert on Chopin, or Chopinist, alive and nicknamed the "Chopinzee." The author attributes his fame to onstage behavior more than musical skill. For example, he muttered, made faces and lectured during recitals saying that was necessary to express his artistic soul. He saw visitors dressed in a smelly, old gown and other garments he claimed were Chopin's. He made other pianists squirm for fear he would disrupt their performance and was not taken seriously by his colleagues.