Napoleon (who by this time was Emperor of France) wanted to use these German states as a buffer between France and any invasion by Austria or Prussia. Austria played right into his hands in 1805 when she attacked Bavaria. Napoleon destroyed both the Prussian and Austrian armies in a campaign that ended in the surrender of the Austrian General Mack in December 1805 and the devastating battle of Austerlitz. The German states of Bavaria , Baden and Wurttemberg who had allied with the French were now well rewarded. Bavaria gained kingdom status and several territories including Tyrol. Over the next few years Napoleon consolidated his hold of these vassal states by marriage and by awarding territories, announcing on 12 July 1806 the formation of the Confederation of the Rhine which would include all German states except Prussia, together with France and the Grand Duchy of Warsaw. This was the death knell for the Holy Roman Empire and in August 1806 the states of the confederation left the Holy Roman Empire and Emperor Franz II became Franz I of Austria.
In the campaigns that followed Bavaria acted much more like a weaker partner with France rather than a vassal state or ally. In 1809 Bavaria was a frontline state against Austria with many of the early clashes taking place on Bavarian soil. Bavarian troops saw defeat with the French at Aspern-Essling and then victory at Wagram but the Tyrol rose in revolt and it took the Bavarian months to put down the uprising. 1812 saw Bavaria supply the Grande Armee with VI Corps for the Russian campaign and elements fought at the battle of Borodino but following the disastrous result of the campaign they finally decided to desert Napoleon's cause just before the battle of Leipzig. The Bavarians tried to cut off the French armies' retreat but failed to do so at the battle of Hanau. In 1814 the Tyrol went back to Austria, and Salzburg was also handed back in 1815. Following Napoleon's flag had gained the Bavarians little but bloodshed, but knowing when to desert their former master they also escaped being carved up by the allies. For their part the French never really appreciated the usefulness of their Bavarian allies and viewed them with contempt.
During the 1790s the Bavarian army was reformed mainly due to the influence of the American Benjamin Thompson (later Graf von Rumford) who although mainly a chemist (and inventor of the coffee percolator) altered their uniform and introduced a new small artillery piece.
Infantry initially had two battalions per regiment each with four companies, each company about 150 men strong which rose to 168 in wartime. Light infantry consisted originally of two regiments known as Feldjager, a Tyrolean jager unit was formed in 1807 but was disbanded in 1811.
Cavalry consisted of Cuirassiers, dragoons and Chevauxlegers. The Cuirassiers originally consisted of two regiments but in 1799 the 2nd Cuirassiers were converted to become the 4th Chevauxleger and in 1804 the 1st Cuirassiers became the 1st Dragoons, the Cuirassiers reappeared after 1815. Until 1815 the Cuirassiers did not wear armour but were equipped with a heavy sword and a brace of pistols. The Dragoons wore the same uniform as the Cuirassiers and also consisted of two regiments. In 1811 the dragoons were converted to Chevauxleger. The Chevauxleger (light cavalry) regiments comprised four squadrons of 150-180 men per squadron but normally had only horses for a single squadron. In 1813 a lancer regiment was raised which copied the Austrian lancer uniform.
Artillery increased to regimental strength early on during this period and consisted of 2 battalions - the 1st or horse artillery battalion and the 2nd or foot artillery battalion. Each battalion had four companies of 150 men, six guns and two howitzers per company. Rank and file carried pistols and short swords with the foot artillery being issued muskets in 1811 while horse artillery had cavalry sabres. The Bavarian army was one of Napoleon's most important German allies and the colourful and distinctive uniform of their troops during this period has made them a favourite among wargamers.