Lawrence III is a self-styled collector, appearing as the main antagonist in The Power of One. Many refer to him as explicitly a Pokémon collector, though there is no evidence that he had any Pokémon himself prior to the movie. His Japanese voice actor is Takeshi Kaga, while his English voice actor is Neil Stuart.
He travels about in his airship, known as 飛行宮 Hikōkyū (literally, "Flying Palace"), which is about the size of a small city, and gathers artifacts from around the world. Despite the scope of his collection, however, he remains rather shortsighted about the world, with his entire plot to capture Lugia reflecting this; his not taking into account the disruption of the natural forces governed by the legendary birds leads to his downfall.
Very little is known about his past, with the only concrete information given by him in the movie. The first object in his collection was an Ancient Mew card, and it remains the only thing remaining in his possession at the end of the movie, inspiring him to continue his collection on a more modest scale. His family is equally mysterious, with his only known relative, his mother, being stated as having died.
(Source: Bulbapedia)