It was not until the second half of the 1800s that Italy and Germany became unified nation-states, which was long after the other major powers in Europe. Nationalism proved to be the unifying force in bringing these countries together.
Both Count Cavour and Giuseppe Garibaldi worked to unite different areas of Italy. Cavour united the northern states of Italy while Garibaldi joined southern Italy to northern Italy. The Papal States, which included Rome, became the last to join Italy. Victor Emmanuel became the first king of a united Italy.
Through war and by appealing to the nationalist feelings of the people, Otto von Bismarck led Prussia as the main force in the unification of Germany. Bismarck was aggressive in his actions which showed his belief in Realpolitik, which justifies all means to achieve and hold power. The Franco-Prussian War led to the creation of the German state.