Ambition, unrestrained by caution, uncontrolled by moderation, has its inevitable end. An empire built upon victory, trusting solely to military genius, prepares for itself the elements of its overthrow. This fact Napoleon was to learn. In the outset of his career he opposed a new art of war to the obsolete one of his enemies, and his path to empire was over the corpses of slaughtered armies and the ruins of fallen kingdoms. But year by year they learned his art, in war after war their resistance grew more stringent, each successive victory was won with more difficulty and at greater cost, and finally, at the crossing of the Danube, the energy and genius of Napoleon met their equal, and the standards of France went back in defeat. It was the tocsin of fate. His career of victory had culminated. From that day its decline began. [=Aims and Intrigues in Portugal and Spain=] It is interesting to find that the first effective check to Napoleon's victorious progress came from one of the weaker nations of Europe, a power which the conqueror contemned and thought to move as one of the minor pieces in his game of empire. Spain at that time had reached almost the lowest stage of its decline. Its king was an imbecile; the heir to the throne a weakling; Godoy, the "Prince of the Peace," the monarch's favorite, an ambitious intriguer. Napoleon's armies had invaded Portugal and forced its monarch to embark for Brazil, his American domain. A similar movement was attempted in Spain. This country the base Godoy betrayed to Napoleon, and then, frightened by the consequences of his dishonorable intrigues, sought to escape with the king and court to the Spanish dominions in America. His scheme was prevented by an outbreak of the people of Madrid, and Napoleon, ambitiously designing to add the peninsula to his empire, induced both Charles IV. and his son Ferdinand to resign from the throne. He replaced them by his brother, Joseph Bonaparte, who, on June 6, 1808, was named King of Spain. [=The Bold Defiance of the People of Spain=]