The Siege of Danzig during the War of the Polish Succession. It is said that this siege in 1734 was the first time that French and Russian forces met on the field of battle as foes.
The War of the Polish Succession, or Election, is a fascinating study in the politics and world of the mid 18th century -- a dynastic Europe that had not yet been ripped by the French Revolution and its dramatic impacts. This war would rage from 1733 to 1738, and hardly gains a mention in most history books -- a mere footnote between the larger War of Spanish Succession and the War of Austrian Succession that begin shortly after the struggle for Poland came to an end. To add to the intrigue here, there was a book published in 1901 by the Crown Prince Vajiravudh of Siam (Thailand) on this very war! He would become King Rama VI upon becoming king in 1910, and reigned until 1925. You can read it here: http://archive.org/stream/warofpolishsucce00vajirich#page/n5/mode/2up
Stanislaus I Leszczynski of Poland & Lorraine by Jean-Marc Nattier
King Louis XV (1715-1774) of France married the daughter, Marie (+1768), of the one-time Polish king, Stanislaus I Leszczynski (he reigned from 1706-1709), in 1725. This marriage would assure that Stanislaus had a powerful ally, and that France would be pulled into the affairs of Poland.
Augustus III, King of Poland and Elector of Saxony by Louis de Silvestre (1675-1760)
The dispute leading to our War of the Polish Succession itself began when Augustus II (1697-1706, 1709-1733), Elector of Saxony and King of Poland, died in 1733. The Polish nobility elected one of their own in 1733 (Poland was, after all, an electoral monarchy), the before-mentioned Stanislaus I Leszczynski. He had briefly reigned during the Great Northern War of 1700-1721 until the Battle of Poltava in 1709, relying as he did on Swedish support. Stanislaus could count on at least the tepid support of son-in-law Louis XV, along with that of Spain and Savoy in Italy. This election result was not acceptable to Russia, under Czarina Anna (1730-1740), however, who preferred the son of the previous king, and ally, Augustus III. Certainly, too, the fact that Stanislaus had sided with Sweden against Russia earlier made him a totally unacceptable candidate in his own right. Thus, with the backing of Holy Roman Emperor Charles VI (1711-1740), the Russians invaded in 1734 to place Elector Augustus III of Saxony (1734-1763) on the throne of Poland. The battlelines were drawn, with significant powers on both sides. Great Britain and the Netherlands remained neutral.
Interestingly, the fighting would not include any major battles, though there would be campaigns in Poland itself, Italy, and the Rhineland. The Treaty of Vienna, signed in 1738, that ended the war generally acknowledged the situation on the ground after the campaigns. It stipulated:
--Augustus III will remain on the throne of Poland, much to the delight of Russia & Austria.
-- Stanislaus will be given title to the Duchy of Lorraine on the French border and within the Holy Roman Empire. After his death, it will pass to his father-in-law, Louis XV & France, (this would happen in 1766). Lorraine had been captured by France, as the Duke of Lorraine married the daughter of HRE Charles VI in 1736, aligning himself with Austria and the side of Augustus III.
-- The unseated Duke of Lorraine, Francis Stephen (later Holy Roman Emperor!), will replace the extinct Medici line as Grand Duke of Tuscany in Italy. The last Medici Grand Duke, Gian Gastone (1723-1737), had just died in 1737 without heir.
-- The Kingdoms of Sicily & Naples will go to Spain after their short-term time as Austrian possessions, with King Philip V of Spain giving them to his son, Charles of Parma, as an independent Kingdom of the Two Sicilies (while he would give the Duchy of Parma in Italy to Austria in return). This merely confirmed the military result of the Italian campaigns of 1735.
-- Finally, the Kingdom of Savoy, in modern Italy, will receive Sardinia in place of Sicily, which they would cede to Spain.
It was a rather different world that would allow for such shuffling of monarchs and territories! This is not a time of total war. Even the winner has to make concessions.
Certainly it did not bode well for Poland to have their monarch essentially dictated to them by Russia. This was not a kingdom long for this world...
[cf. A Political & Cultural History of Modern Europe by Hayes, The Columbia Encyclopedia]