Trans-Alpine duchy straddling France, Italy and Switzerland; raised from County of Savoy in 1416, key player in Italian politics and ancestor of unified Italy.
Merged into the unitary Kingdom of Sardinia under the Perfect Fusion of 1847, ending its existence as a distinct duchy within the Savoyard composite monarchy; the Savoy territory itself was subsequently ceded to France in 1860 under the Treaty of Turin.
Foundational scholarly history of the first two centuries of the House of Savoy; Cambridge University Press. Confirmed via Cambridge UP catalogue, Internet Archive, and American Historical Review.
Narrative history of the duchy from its Alpine origins through the modern era; Fonthill Media. Confirmed via Fonthill Media website, Amazon, and AbeBooks.