The Royal Saxon Army (with a strength not more than 2 divisions) was under the command of the Rulers of Saxony

Rulers of Saxony

This article lists Dukes, Electors, and Kings ruling over different territories named Saxony from the beginning of the Saxon Duchy in the 9th century to the end of the Saxon Kingdom in 1918.-Dukes of Saxony:...

. With the formation of the Confederation of the Rhine

Confederation of the Rhine

The Confederation of the Rhine was a confederation of client states of the First French Empire. It was formed initially from 16 German states by Napoleon after he defeated Austria's Francis II and Russia's Alexander I in the Battle of Austerlitz. The Treaty of Pressburg, in effect, led to the...

 by Napoleon the Royal Saxon Army joined the French "La Grande Armée

La Grande Armée

The Grande Armée first entered the annals of history when, in 1805, Napoleon I renamed the army that he had assembled on the French coast of the English Channel for the proposed invasion of Britain...

" along with 37 other German states. The commander of the Royal Saxon Army at this time, was Frederick Augustus I of Saxony

Frederick Augustus I of Saxony

Frederick Augustus I was King of Saxony from the House of Wettin. He was also Elector Frederick Augustus III of Saxony and Duke Frederick Augustus I of Warsaw...

. He was a staunch ally of Napoleon Bonaparte.
The founder of the standing army in Saxony was Elector Johann Georg III

John George III, Elector of Saxony

Johann Georg III was Elector of Saxony from 1680 to 1691.-Early life:Johann Georg was the only son of the Elector Johann Georg II and Magdalene Sybille of Brandenburg-Bayreuth....

. He convinced the Saxon Estates in 1681 that the established practice of in case of war hiring mercenaries and dismissing them in peace, was as costly as the formation of a standing army.