This is a list of numbered Regiments of Foot of the British Army from the mid-18th century until 1881, when numbering was abandoned.
The rank of regiments of the British Army was first fixed during the Nine Years' War. Doubts as to the respective rank of regiments fighting in the Spanish Netherlands led William III to command a Board of General Officers meeting on 10 June 1694 to establish the order of precedence of the various units. Further boards were convened by Queen Anne and George I in 1713 and 1715 to decide the rank of regiments raised after 1694.
The rank or precedence of regiments was fixed by the following criteria:
This led to anomalies, such as the Royal Irish Regiment, raised in 1684, being ranked as the 18th of the line, junior to eleven regiments raised between 1685 and 1688.
While regiments were known by the name of their colonel, or by their royal title, the number of their rank was increasingly used. Thus, in the Cloathing Book of 1742, which illustrated the patterns of uniforms worn by the King's forces, the regiments of foot are designated simply by numbers.
The substitution of numbers for names was completed by a clothing regulation of 1747 and a royal warrant of 1751. The 1747 document, which used numbers for the regiments throughout, decreed that no colonel was "to put his Arms, Crest, Device or Livery on any part of the Appointments of the Regiment under his command." Furthermore, in the centre of the regiment's colours was to be "painted or embroidered in gold Roman characters the number of the Rank of the Regiment". The warrant, dated 1 July 1751, repeated the instructions of the 1747 regulation and provided that regiments should in future be known by their numbers only.
As the size of the army expanded and contracted during the various conflicts of the 18th and 19th centuries, junior regiments were raised and disbanded. Accordingly, there were often a number of different regiments that bore the same number of different periods. Additionally, there were occasional partial renumberings. For instance, in 1816 the 95th (Rifle) Regiment of Foot was renamed the Rifle Brigade, without a number. The existing 96th–103rd regiments were redesignated as the 95th–102nd.