Some years before, the Mexican Government under the clerical and militarist regime had made a contract with a Swiss banker who for a payment of $500,000 had received bonds worth more than fifteen times the value of the loan. When, therefore, the Mexican Congress undertook to defer payments on a foreign debt that included the proceeds of this outrageous contract, the Governments of France, Great Britain, and Spain decided to intervene. According to their agreement the three powers were simply to hold the seaports of Mexico and collect the customs duties until their pecuniary demands had been satisfied. Learning, however, that Napoleon III had ulterior designs, Great Britain and Spain withdrew their forces and left him to proceed with his scheme of conquest. After capturing Puebla in May, 1863, a French army numbering some thirty thousand men entered the capital and installed an assemblage of notables belonging to the clerical and conservative groups. This body thereupon proclaimed the establishment of a constitutional monarchy under an emperor. The title was to be offered to Maximilian, Archduke of Austria. In case he should not accept, the matter was to be referred to the "benevolence of his majesty, the Emperor of the French," who might then select some other Catholic prince. On his arrival, a year later, the amiable and well-meaning Maximilian soon discovered that, instead of being an "Emperor," he was actually little more than a precarious chief of a faction sustained by the bayonets of a foreign army. In the northern part of Mexico, Juarez, Porfirio Diaz,--later to become the most renowned of presidential autocrats,--and other patriot leaders, though hunted from place to place, held firmly to their resolve never to bow to the yoke of the pretender. Nor could Maximilian be sure of the loyalty of even his supposed adherents. Little by little the unpleasant conviction intruded itself upon him that he must either abdicate or crush all resistance in the hope that eventually time and good will might win over the Mexicans. But do what they would, his foreign legions could not catch the wary and stubborn Juarez and his guerrilla lieutenants, who persistently wore down the forces of their enemies. Then the financial situation became grave. Still more menacing was the attitude of the United States now that its civil war was at an end. On May 31, 1866, Maximilian received word that Napoleon III had decided to withdraw the French troops. He then determined to abdicate, but he was restrained by the unhappy Empress Carlotta, who hastened to Europe to plead his cause with Napoleon. Meantime, as the French troops were withdrawn, Juarez occupied the territory.