The state of Moscow, growing fat at the expense of the surrounding territory, finally became strong enough to risk open rebellion against its masters, the Tartars. It was successful and its fame as the leader in the cause of Russian independence made Moscow the natural centre for all those who still believed in a better future for the Slavic race. In the year 1458, Constantinople was taken by the Turks. Ten years later, under the rule of Ivan III, Moscow informed the western world that the Slavic state laid claim to the worldly and spiritual inheritance of the lost Byzantine Empire, and such traditions of the Roman empire as had survived in Constantinople. A generation afterwards, under Ivan the Terrible, the grand dukes of Moscow were strong enough to adopt the title of Caesar, or Tsar, and to demand recognition by the western powers of Europe.