Kingdom of Two Sicilies: Italian Lineage The Kingdom of the Two Sicilies, commonly known as the Two Sicilies even before formally coming into being,[1] was the largest and wealthiest of the Italian states before Italian unification. It was formed of a union of the Kingdom of Sicily and the Kingdom of Naples in 1816 and lasted until 1860, when it was annexed by the Kingdom of Sardinia, which became the Kingdom of Italy in 1861. The Two Sicilies had its capital in Naples and was commonly referred to in English as the "Kingdom of Naples". The kingdom extended over the Mezzogiorno (the southern part of mainland Italy) and the island of Sicily.