Martin Luther: The Christian Between God and Death, by Richard Marius
Most of Martin Luther's biographers end their books in the 1520s, some 20 years before Luther's death. This allows them to leave Luther as a revolutionary (and theological) hero, rather than as an establishment curmudgeon. And it enables them to avoid dealing with the older Luther's repugnant attacks on Catholics, Jews, Turks and fellow Protestants.
Richard Marius follows this tradition by ending with the 1525 quarrel between Luther and Erasmus over the freedom of the will. But Marius finds even the young Luther repugnant. Rather than idealizing the youthful revolutionary, Marius sees in his rebellion the seed of subsequent religious wars. He even ventures the ahistorical surmise that modern European history would have been "more serene" and less disfigured by hatred and massacre had Luther either been dissuaded from entering the monastery or died a martyr at Worms.