The fourth volume of Pawel Jasienica's magnificent epos of Polish history, 'Calamity of the Realm,' covers part of the 17th century and deals with a multitude of wars with Muscovy, Sweden, the Tartars, Cossacks, and Turks. It also describes the complex relations between Poland and France. Jasienica describes in colorful detail the many campaigns of Jan Sobieski, in which he demonstrated a tactical skill that won him battles against enemies far stronger in numbers.