The Polish throne, vacant upon the death of Augustus II of Saxony on February 1, 1733,  is claimed by both his son, Augustus III, and by Stanisław Leszczyński, father in law of King Louis XV of France.While a body double ostensibly leaves Brest by sea, Stanisław crosses Germany incognito to arrives at Warsaw on September 8.

Stanislas is  elected king of Poland by the diet on September 12.

Russia and Austria, both of whom back Augustus III, immediately invade Poland.

Stanisław, who does not have a proper army, has to take refuge by September 22 in Danzig (now known as Gdansk), there to await the French help he has been promised.

Augustus III, protected by Russian forces at Warsaw, is proclaimed king on October 5.

Great Britain, the Dutch Republic, Sweden, Denmark and the Republic of Venice, recognizing that Austro-Russian aggression against Poland is the casus belli, pledge to remain neutral.

Spain, coveting the Kingdom of Naples and Sardinia, which the Duke of Milan wants, sides with France.