The autocracy and the unity of Russia were consolidated together by the genius of Ivan III., who made their emblem the double-headed eagle, and by Ivan IV., who sacrificed to them a sea of blood. The municipal autonomies and the petty independent princes frowned, but Russia became a true nation; at the beginning of the sixteenth century, the brilliant age of the monarchical principle, no European sovereign could boast of being so thoroughly obeyed as the sovereign prince of Moscow. The radical concept of omnipotent power, not tempered as in the West by the humanity of Catholicism, at once rushed headlong to oppression and slavery. The ambitious regent Boris Godonof was not long in attaching the serfs to the soil, and upon the heels of this unscrupulous act followed the dark and bloody days of the false Demetrii, in which the serf, irritated by the burden of his chains, welcomed, in every adventurer, in every impostor, a Messiah come to redeem him. Then the Poles, the eternal enemies of Russia, seized the Kremlin, the Swedes threatened to overcome her, and the nation seemed ready to perish had it not been for the heroism of a butcher and a prince; a suggestive example of the saving strength which at supreme moments rises up in every nation. But one more providential tyrant was needed, the greatest of all, the most extraordinary man of Russia's history, of the house of Romanoff, successor to the extinct dynasty of the Terrible Ivans. "Terrible" might also be applied to the name of the imperial carpenter whose character and destiny are not unlike those of Ivan IV. Both were precocious in intellect, both were self-educated, and both cooled their hot youth in the hard school of abandonment. Out of it came Peter the Great, determined at all costs to remodel his gigantic empire.