Titian, Charles V on Horseback in Mühlenberg, 1548Oil on canvasMuseo del Prado, Madrid.

The majesty of power. The power of majesty. Both emerge clearly from John Julius Norwich’s lucidly written and life-enhancing Four Princes, an account of a time of turmoil, adventure, and development. As he writes, has there been a half-century like it? Here, packed into the space of a lifetime, are the High Renaissance, Luther and the Reformation, the exploration of the Americas, and a series of memorable monarchs, each of whom left an indelible imprint on the history of the European world.

Both with this splendid imperial a ...