When did Sardinia become part of Italy?
Crema, Lombardy
By the 1859 Treaty of Zurich which ended the Austro-Sardinian War, Austria ceded Lombardy, including Crema, to France, who then immediately ceded it to Sardinia. This formed part of the "Risorgimento", which saw Sardinia become the Kingdom of Italy in 1861. In 1946, the Kingdom became the modern Italian Republic.
Kingdom of Sardinia
In 238 BC Sardinia became, along with Corsica, a province of the Roman Empire. The Romans ruled the island until the middle of the 5th century, when it was occupied by the Vandals, who had also settled in north Africa. In 534 AD it was reconquered by the Romans, but now from the Eastern Roman Empire, Byzantium. It remained a Byzantine province until the Arab conquest of Sicily in the 9th century. After that, communications with Constantinople became very difficult, and powerful families of the island assumed control of the land.