Martin Luther called Nikolaus von Amsdorf a "theologian by nature." He was Luther's close friend and contemporary - born three weeks after Luther but living two decades longer. He was the only nobleman in Luther's inner circle and one of the first Evangelical bishops. Known by his colleagues as a "fierce enemy of all corruption and adulteration of true Lutheran, Evangelical truth," his contributions during the theological controversies after Luther's death shaped numerous articles of the Formula of Concord. Yet, few people today have ever heard of Nikolaus von Amsdorf, let alone his influence on Lutheran theology.