Who described his policy of unification as one of 'blood and iron'?

With the failure of the revolution of 1848 to unify Germany, one phase in the struggle for unification came to an end. Now Germany was to be unified not into a democratic country by the efforts of revolutionaries but by the rulers into a militaristic empire. The leader of this policy Bismarck who belonged to a prussian aristocratic family. He wanted to preserve the predominance of the landed aristocrats and the army in the united German state and to achieve the unification of Germany under the leadership of Prussian monarchy. He described his policy of unification as one of 'blood and iron'. The policy of 'blood and iron' meant a policy of war.