In the midst of this period a war broke out concerning the succession to the Polish throne.

The father-in-law of the French king was one claimant; Austria supported his opponent.

A common hostility to Austria once more drew France and Spain together, and they were joined by the King of Sardinia, who hoped through this alliance to wrest Milan from Austria and add it to his own territory of Piedmont.

The neutrality of England and Holland was secured by a promise not to attack the Austrian Netherlands, the possession of any part of which by France was considered to be dangerous to England's sea power.

The allied States declared war against Austria in October, 1733, and their armies entered Italy together; but the Spaniards, intent on their long-cherished projects against Naples and Sicily, left the others and turned southward.