Can someone please explain Martin Luther to me?

Martin Luther was a Catholic Monk who because of his knowledge was summoned to work at the Vatican. He became unhappy with the Vatican's lavish spending of money on itself instead of the people and began writing and posting protests about it. The Vatican ordered him to to stop, but he refused and was excommunicated for it. He retaliated by starting another sect of Christianity called Protestantism, which many people liked. Protestant comes from the word, protesters.