The campaign finished and with the consequent disbandment of troops, King Ferdinand decided to permanently keep that force on the rolls, making one of the first standing armies in Europe since the Roman Empire.

[citation needed] On 28 August 1632, on the initiative of Philip IV, a special corps of troops was ordered to be formed with veteran soldiers, reenlistments and knights of noble ancestry - men so skilled that they only took arms when the monarch assumed command in person, designating it "King's Guard Colonelship."

Its first colonel, Count Duke of Olivares, Don Gaspar de Guzmán, whose post was the recently created "King's Guard Colonelship," was in command of very distinguished soldiers of great renown.

It gained glory in the Spanish War of Succession and the Italian Campaigns (1718-1749), eventually it received the name King's Infantry Regiment on 7 January 1766.

Traditionally, as the regiment is linked to the Spanish royal family and to the sovereign in his/her duty as Captain General and Commander-in-Chief of the Armed Forces, all the Princes of Asturias since 1862 are enrolled as Honorary soldiers in the 1st Company.

To commemorate Spain's long military tradition, in 1981 King Juan Carlos I accepted the proposal of the Chief of Staff of the Army to establish two companies with historic uniforms and armaments, which could render honors and participate in special ceremonies.

The first honor guard company wears the white infantry uniform of this period, with green facing and botoneras (metal buttons) on the waistcoat and dress coat.

These picked men marched at the head of the regiment, escorted the colors and were expected to form the vanguard when storming a fortified position.

1 parades detachments of up to company strength, plus the regimental band, in the full dress uniform of the Spanish line infantry, as worn during the reign of King Alfonso XIII (1902-1931).

In addition to these regular functions, the regiment has participated in actions on behalf of the civilian population when required, e.g. environmental cleaning carried out in Galicia following the sinking of the ship Prestige.