The Grenadier Guards is the most senior infantry regiment of the British Army, being at the top of the Infantry Order of Precedence. It can trace its lineage back to 1656 when Lord Wentworth's Regiment was raised in Bruges to protect the exiled Charles II. In 1665, this regiment was combined with John Russell's Regiment of Guards to form the current regiment, known as the 1st Regiment of Foot Guards. Since then, the regiment has filled both a ceremonial and protective role as well as an operational one. In 1900, the regiment provided a cadre of personnel to form the Irish Guards; while later, in 1915 it also provided the basis of the Welsh Guards upon their formation.

Infantry is a specialization of military personnel who engage in warfare combat. Infantry generally consists of light infantry, irregular infantry, heavy infantry, mountain infantry, motorized infantry, mechanized infantry, airborne infantry, air assault infantry, and naval infantry. Other types of infantry, such as line infantry and mounted infantry, were once commonplace but fell out of favor in the 1800s with the invention of more accurate and powerful weapons.