Life was to become even more dangerous and precarious for the British army as it become embroiled in the highly difficult task of containing the expansion of Revolutionary and then Napoleonic France. The army would therefore be forced to expand to an unusually large size and would be strained to its limits. The prominent role played by the British army in ultimately defeating Napoleon would restore its pride and prestige both at home and overseas.

In the period following victory in 1815, the British army was regarded as the fire brigade of the Empire - being sent to where ever there were disturbances or problems. It would become involved in countless small wars in far flung corners of the globe, most of which would be successful endeavours. However, the army would be sorely tested by the events of the Crimean war and the Indian Mutiny. The problems encountered in these actions provided the rationale for the Cardwell army reforms which were implemented progressively from the late 1860's to the early 1880's.

The numbering system used by the British army in order to determine precedence was first used in 1751. The year 1782 is interesting because it is the first time that many of these regiments were associated with a specific local area. Theoretically, this was to be where their depot was to be based and their recruiting to take place. However, constant strategical and manpower needs meant that these regiments could be posted anywhere and were keen to take recruits from wherever they could find them. In this period of history, the numbers were the more important of the designations and would be used on a day to day basis. However, the territorial titles would later form the basis of the next major overhaul of the regimental system almost exactly 100 years later: the Cardwell Army reforms.