Like Harry Potter? The book that was rejected out of hand by the author's agent because he didn't represent children's books? The one that was only salvaged by an assistant who read the book over her lunch break in order to give the author some encouragement because its unusual mailing binder caught her attention? The one that only went on submission because that assistant walked it down the hall, plopped it onto her boss's desk and insisted that he read it over his objections?
You mean the book that began with Hermione's mom and dad seeing the green flash from Harry's parents' death because they were on holiday with their daughter and close enough to Godric's Hollow to witness it, even though non-magical folk shouldn't have been able to? Because that was how the rejected version started.
In other words "Harry Potter" wasn't rejected by multiple editors - a different book with a different beginning was rejected by multiple editors. The rejected book was more old fashioned and less polished, and the only reason it was picked up at all was because the imprint was new, had nothing on its slate and the editor's kid happened to pick up the first pages and love them.
Even with that, the book was given a half-sized print run and a half-sized advance because the editor didn't think it would sell well.
Look at another example - Eragon. It was a flop by every measure you could imagine. It nearly bankrupted the author's parents' press, which is who originally published it. Again, it was an editor's kid who happened upon it and pulled it out of the bin. The kid was out with his dad and saw the author in costume attempting to do a book event at a bookshop. The kid saw the cover of the book and told his dad that dad's publishing company should buy the book.
Twilight: also widely rejected. So widely that it was literally in the author's agent's trash bin when her assistant, who had read the opening pages, pulled it out and asked the agent to re-read it. The book was "too long" and "lacked conflict," etc... then it sold.
Basically, rarely is the rejected book the one that gets published. Also, you should be very, very nice to agent-assistants, as they can literally pull your book out of the fire, and also if you see an editor's kid, they basically control your novel's destiny.