At the very moment that Cavour thought he had lost the game, he had won it.  On the same day, April 19, Count Buol,—­somewhat, it is said, against his better judgment, but yielding to the Emperor, who again yielded to the military party,—­sent off a contemptuous rejoinder to the English proposals.  Ignoring all suggestions, the Austrian Minister said that they would themselves call upon Piedmont to disarm.  Here, then, was the famous acte d’agression.  Napoleon could not escape now.

The fact that this happened simultaneously with Sardinia’s submission to the will of Europe was a wonderful piece of luck, which, as Massimo d’Azeglio said, could happen only once in a century.  When the Austrian Government took the irrevocable step, it did not know yet that the whole onus of breaking the peace would fall upon it.  Nor, it must be remembered, did it know the test of the treaty between France and Sardinia, and in view of the French Emperor’s recent conduct it may well have become convinced that no treaty at all existed.  Hence it is probable that Austria flattered herself that she would only have to deal with weak Sardinia.

The Chamber of Deputies was convoked on April 23 to confer plenary powers on the king.  Many deputies were so overcome that they wept.  Just as the President of the Chamber announced the vote, a scrap of paper was handed to Cavour, on which were written the words in pencil:  “They are here; I have seen them.”  It was from a person whom he had instructed to inform him instantly when the bearers of the Austrian Ultimatum arrived.  They were come; angels of light could not have been more welcome!  Cavour went hastily out, while the House broke into deafening cries of “Long live the king!” He said to the friend who brought the message, “I am leaving the last sitting of the last Piedmontese Chamber.”  The next would represent the kingdom of Italy.

The Sardinian army to be placed on a peace-footing, the volunteers to be dismissed, an answer of “Yes” or “No” required within three days—­these were the terms of the Ultimatum.  If the answer were not fully satisfactory His Majesty would resort to force.  Cavour replied that Piedmont had given its adhesion to the proposals made by England with the approval of France, Prussia and Russia, and had nothing more to say.  No one who saw the statesman’s radiant face would have guessed that less than a week before he had passed through so frightful a mental crisis.  He took leave of Baron von Kellersberg with graceful courtesy, and then, turning to those present, he said, “We have made history; now let us go to dinner.”

The French Ambassador at Vienna notified to Count Buol that his sovereign would consider the crossing of the frontier by the Austrian troops equivalent to a declaration of war.