Martin Luther
Church Government
Luther made tremendous contributions in this area. From the moment he more or less abolished the Catholic Church, even while he was still hiding in the Wartburg, he found he had to make rulings regarding behavior, or to settle disputes. Because he had rejected so much of the the Catholic Church, he had to feel his way toward a new church, which he did reluctantly but without flinching from the task. Later reformers could look at what Luther had done and use it as a starting point, but Luther himself had to find his way in the dark. It was quite an accomplishment.
One of the key innovations was his creation of the visitation. This was where a committee of pastors travelled to other churches to see how they were doing. This was akin to what bishops did within their sees, so it's not like Luther thought it up whole cloth, but by not only instituting it but also by writing out a whole set of rules for the visitors, he created one of the foundation stones for the governance of the Lutheran Church. The first visitations were in 1527, and Luther himelf was among the visitors.