At the time of the outbreak of wars with revolutionary France (1792-1799), the Prussian army was still radiant with the fame of great successes during the Seven Years' War (1756-1763), and the memory of such victories as the Battle of Rossbach (1757) or Lutynia (1757) was still alive. It was also widely regarded as probably the best in Europe. However, already in the 1770s, it began to undergo a kind of erosion and ossification. Its combat value was becoming more and more debatable. The Prussian army was still able to wage a campaign against France with some success in 1792-1795, but already in the course of the 1806 campaign it suffered a devastating defeat. It is not surprising that the battles of Jena and Auerstädt became synonymous with defeat in the Prussian army, and at the same time launched a process of far-reaching changes. These reforms also affected - not surprisingly - the Prussian infantry. The so-called line infantry composed of musketeers and grenadiers. In 1806 it had 147 battalions, while in March 1813 Prussia was able to deploy 12 line infantry regiments. However, in the period 1813-1815 this number was increased by co-opting reserve infantry battalions to 32 regiments. Before the 1806 campaign, the Prussian line infantry regiment (musketeer or grenadier) consisted of 2 battalions, each with 805 to 830 full-time soldiers. However, in 1808 the regiment's structure changed and it consisted of a fusilier battalion and two musketeer battalions. Each battalion consisted of 4 companies. It is worth adding that the shooting equipment of the Prussian line infantry - in contrast to the Friarian era - was diverse and consisted of several types of flintlock rifles. When it comes to training it, it should be said that it was generally good for regiments formed before 1813 and average for those formed in the period 1813-1815. Undoubtedly, however, morale and the will to fight were often at a very high level.
The Battle of Waterloo was fought on June 18, 1815 and was the last battle commanded by Napoleon Bonaparte with the French forces. It is assumed that on the French side, about 65,000 soldiers and 250 guns took part in the battle, while on the Anglo-Dutch and Prussian sides, a total of about 123,000 men, with about 160 guns (excluding Prussian artillery) fought. The French side was led, of course, by the emperor of the French, the allies - Arthur Wellesley, Fr. Wellington, and the Prussians - Gebhard von Blücher. British-Dutch troops, awaiting the arrival of the Prussians, but also based on the experiences of Fr. Wellington, learned from the fighting in Spain, adopted a defensive stance, and their position was supported by farm buildings. The battlefield with boggy ground, soaked with water after intense rainfall, also favored the defenders, as it made it difficult to develop a cavalry attack. The battle began around 11.30 with the French artillery cannonade, and later - with the attacks of the French infantry on the British-Dutch positions. Initially, the fight for the Hougomont farm was fought, but later also on the right flank and in the center of the Allied formation. The next phase of the battle was the British cavalry charges, which were intended to relieve the fighting infantry, which initially brought great success to the British, but were finally repulsed with considerable losses. Despite fierce fighting and attacks led by Marshal Ney, around 4.30 pm, the British positions seemed to be intact, and the Prussians, commanded by Gebhard von Blücher, were already approaching the battlefield. Finally, around 19.30, the 1st Prussian Corps entered the fight - it meant that the scales of victory were tilted towards the allies, despite the Old Guard's attack on British positions. The immediate aftermath of the Battle of Waterloo was Napoleon's abdication and the end of the Napoleonic era in the history of Europe.