What is the origin of this quote?

“In the end, some of them repented. They became my guardians, my protectors, even my friends. They sheltered me from the bloody end which my brethren had met at the hands of their kind. But a day of kindness does not undo an age of cruelty. It was too late. For l am the last, and today I must go - and I leave behind a void that can never again be filled”