War of the Polish Succession, 1733–35

In 1733, King Augustus II of Poland (a Saxon by birth) died. The Polish Sejm , an assembly of nobles, elected Stanislaus Leszczyński, a Polish nationalist, as their king. (Poland customarily elected its kings.) A minority of Poles and the countries of Russia, Austria, and Saxony supported as king Augustus's son, who they believed would act in their interests. France, Spain, and Sardinia backed Leszczyński.

The war began with the invasion of Poland by Russian forces (later joined by Saxons) in 1733. Leszczyński was driven out in 1734, and was replaced by the invaders' claimant, who became king as Augustus III. Defeat of a French relief force ended effective resistance in Poland, though civil strife between Polish supporters of the rival claimants continued into 1735.

Hostilities erupted in other parts of Europe. French armies seized the duchy of Lorraine (a possession of the Austrian Hapsburg family) and then fought inconculsively against the Russians and Austrians in the Rhineland region of Germany. In Italy, French, Spanish, and Sardinian forces hoped to seize the Hapsburg domains of Milan, Sicily, and Naples, but Austria fought them to a draw.

A peace accord was signed in 1735 and ratified in 1738. Under its provisions, Augustus III was confirmed as king of Poland and Leszczyński was made duke of Lorraine (upon his death the duchy would revert to France). Spain won control of Sicily and Naples, but in return the Austrian Hapsburgs were awarded three duchies in northern Italy that were previously under control of the Spanish Bourbons.