There are periods in the history of most nations when all that has been hallowed by time and custom seems of a sudden to lose its sanctity and bow down before the commanding influence of some new force. These periods are of rare occurrence and generally of short duration. They remind one of those thunderstorms which burst upon us at the close of a sultry August day, unheralded but by the stifling heat of a burning sky, and in a few moments leaving the atmosphere behind them pure and clear and cool. Sudden and unheralded as they appear, they are yet the direct result of a long series of forces, whose ultimate issue might have been accurately predicted did we but thoroughly understand the forces themselves. So, too, it is with great political upheavals. The revolution which drenched the whole of France with blood in 1789 is no more difficult to explain than the thunderstorm which drenches the parched earth with rain on a hot midsummer night. It was simply the reaction after a century of oppression, extravagance and vice. In like manner the great revolution whose development we are about to trace was merely the natural result of long years of tyranny culminating in the fearful carnage of the autumn of 1520. The Revolution in Sweden is, however, in one respect pre-eminent among the great crises known to history. Never was a revolution so thoroughly the work of a single man as that in Sweden. From beginning to end there was one figure whose presence alone infused life into a lukewarm people, and who, working upon the forces which had been forged by years of tyranny, shaped them gradually to his own commanding will. The Revolution in Sweden is the history of Gustavus Vasa. He it was who set the torch, and he, too, pointed out the direction in which the flame should burn.