Kingdom of Sardinia played a significant role in the unification of Italy and became the nucleus of the unified state.

The Kingdom of Sardinia, also known as the Kingdom of Piedmont-Sardinia, was a state in Italy that existed from 1720 to 1861. It was ruled by the House of Savoy and had its capital in Turin.

1. Historical Context:
- In the 19th century, Italy was divided into several smaller states, each with its own ruler.
- The process of Italian unification, known as the Risorgimento, aimed to unify these states into a single nation.
- The Kingdom of Sardinia emerged as a major player in this process due to its strategic location and its relatively liberal and progressive government.

2. Leadership of King Victor Emmanuel II:
- King Victor Emmanuel II of the House of Savoy played a crucial role in the unification of Italy.
- He was a strong and determined leader who pursued a policy of expansion and consolidation of his kingdom.
- Under his rule, the Kingdom of Sardinia embarked on a series of military campaigns and diplomatic negotiations to unify Italy.

3. Role in Wars of Independence:
- The Kingdom of Sardinia actively participated in the Wars of Independence against foreign powers.
- In 1859, it allied with France and fought against Austria in the Second Italian War of Independence.
- The Sardinian forces, led by the skilled statesman and military commander Count Camillo di Cavour, achieved significant victories.

4. Treaty of Plombières:
- The Treaty of Plombières in 1859 between France and the Kingdom of Sardinia laid the foundation for Italian unification.
- The treaty promised French military support to Sardinia in its war against Austria.
- This alliance with France was crucial for Sardinia to gain the upper hand in the war.

5. Annexation of Central Italy:
- As a result of the wars against Austria, the Kingdom of Sardinia annexed several territories in Northern and Central Italy.
- The Grand Duchy of Tuscany, Duchy of Parma, Duchy of Modena, and Romagna region were incorporated into the kingdom.

6. Formation of the Kingdom of Italy:
- In 1861, the Kingdom of Sardinia was renamed the Kingdom of Italy after the proclamation of the Kingdom of Italy by the Parliament of Turin.
- King Victor Emmanuel II became the first king of a unified Italy.
- The Kingdom of Sardinia, through its military victories and political alliances, became the nucleus of the unified Italian state.

In conclusion, the Kingdom of Sardinia played a crucial role in the unification of Italy. Through its leadership, military campaigns, and diplomatic alliances, it expanded its territory and became the foundation of the unified Kingdom of Italy.