Apart from Luther the Reformation itself cannot be understood...
Indeed, whether but for Luther the Reform movement of the sixteenth century would have swept over Europe in the way it did is highly questionable.
It can also be argued that the Reformation was a much wider movement than this, that it occurred, for example, because the economic problems of the early sixteenth century, especially the rising population, meant that the peasants were overstretched and so welcomed an end of payments to Rome while the princes could gain from taking over church land.
Equally it can be argued that the princes were more concerned with the political gains a breaking with Rome, but neither economics nor politics can provide a complete explanation.
This collection of documents attempts to look at the Reformation from every aspects and draws widely from a variety of sources.