The Life of Augustus Hermann Francke: https://archive.org/details/augustushe00guerThe most intriguing biography of the year was undoubtedly that of August Hermann Francke (1663-1727). I am sure most Americans have never heard of him, and yet we owe a lot of our modern Christian practices to Francke and his close friend Philipp Spener. Francke's autobiography (Footsteps of Divine Providence) was long considered a classic, was well-known to John Wesley (who published Francke's works), and was an inspiration to George Müller, but has not been in print in English in about a century. If someone takes the time to make Frankce and Spener known to a modern audience, it will be a great achievement.
Memoirs of Augustus Hermann Francke: https://archive.org/details/memoirsofaugustu00amer
Philip Jacob Spener and His Work: https://archive.org/details/philipjacobspene00rich