After the Congress of Vienna in 1815, Prussia remained among the powers of Europe, but was not as great as Austria, Russia, England, or France.  The German states, some 35 in number, had united in a loose alliance called the German Confederation. (This union was somewhat similar to the United States of America between 1776 and 1789.) Austria was the largest of these states, and was naturally looked upon as the leader of the whole group.  Prussia was the second largest, while next after Prussia, and much smaller, came the kingdoms of Bavaria, Saxony, Hanover, and Wurtemburg.  Bismarck, as prime minister of Prussia, built up a wonderfully strong army.  He did this by means of a military system which at first made him very unpopular with the people.  Every man in the nation, rich or poor, was obliged to serve a certain number of years in the army and be ready at a moment’s notice to join a certain regiment if there came a call to war.

Having organized this army, and equipped it with every modern weapon, Bismarck was anxious to use it to accomplish his purpose.  There were two counties named Schleswig (shles’vig) and Holstein (hol’stin) which belonged to the king of Denmark and yet contained a great many German people.  The inhabitants of Schleswig were perhaps half Danes, while those of Holstein were more than two-thirds Germans.  These Germans had protested against certain actions of the Danish government, and were threatening to revolt.  Taking advantage of this trouble, Prussia and Austria, as the leading states of the German Federation, declared war on little Denmark.  The Danes fought valiantly, but were overwhelmed by the armies of their enemies.  Schleswig and Holstein were torn away from Denmark and put under the joint protection of Austria and Prussia.

This sort of arrangement could not last.  Sooner or later, there was bound to be a quarrel over the division of the plunder.  Now Bismarck had a chance to show his crafty diplomacy.  He made up his mind to crush Austria and put Prussia in her place as the leader of the German states.  He first negotiated with Napoleon III, Emperor of the French, and made sure that this monarch would not interfere.  Next he remembered that the provinces of Venetia, Trentino, and Istria still belonged to Austria, as the Italians had failed to gain them in the war of 1859.  Accordingly, Bismarck induced Italy to declare war on Austria by promising her Venetia and the other provinces in return for her aid.  Saxony, Bavaria, and Hanover were friendly to Austria, but Bismarck did not fear them.  He knew that his army, under the leadership of its celebrated general, von Moltke, was more than a match for the Austrians, Bavarians, etc., combined.