2 of 2 added 15 characters in body

Harry was in possession of all of the Hallows at some point in time, as was Dumbledore. Harry arguably owned all of them for most of Book 7. He had the cloak and the stone inside of the snitch, although he didn't know it until near the end of the book, and he owned the wand, although he didn't know it, nor did he have it for most of the book. He did briefly physically have the wand as well, but that was after he had dropped the Resurrection Stone. Bottom line, Harry was the closest to mastering all of the Deathly Hallows that is mentioned in the books, with Dumbledore as a close second.