Like Germany, Italy used to be a collection of states sharing a similar culture and language. These states would come together in the 19th century and form the Italy we know today.
Before unification, the area today known as Italy was composed of six different states, four of which were under Austrian influence. The remaining two were the Two Sicilies and Sardinia, which were independent.
In 1852, a man named Camillo De Cavour became the prime minister of Sardinia. Backed by the French, who were offered a big chunk of the unified Italy, Cavour's forces invaded Northern Italy, which was controlled by Austria.
Meanwhile, Giuseppe Garibaldi gathered a force of one thousand volunteers (the Red Shirts) and sailed to Sicily, conquering it. They then moved north, capturing more of Italy, then finally meeting up with Cavour's forces. In 1861, the kingdom of Italy was formed, with the king of Sardinia ruling the country.