List of oldest military units and formations in continuous operation


This is a list of oldest military units and formations in continuous operation. In continuous operation here means not units that no longer exist, or recent creations sharing only the name with an older unit.
Please note: Whereas modern standing armies first developed in the 15th century, the defining terminology for contemporary military units and formations, such as company, battalion, regiment etc. mostly arose in the early modern period, during the 16th and 17th centuries.

Oldest active military units still in operation

YearHeraldryNameFounderFounding
location		Current
location		Notes
1248King's Own Immemorial 1st Infantry RegimentFerdinand III of Castile Crown of CastileMadrid, SpainIt was one of the first standing units in Europe since the fall of the Roman Empire, remaining in the order of battle of the Castilian and Spanish armies since its creation. At present the Regiment is the Unit responsible for providing the central seat of Spanish Army Headquarters security, services, and support needed for its functioning.
14791st Infantry RegimentKing Louis XI of France Sarrebourg, FranceFounded in 1479-1480 by King Louis XI as Bandes de Picardie. It became the Légion de Picardie in 1558 during the Italian War of 1551-1559 and then Régiment de Picardie on May 29, 1569. It was ultimately renamed 1er régiment d'infanterie de ligne in 1791 after the military reforms of Louis Le Bègue Duportail. It is now part of the Franco-German Brigade and was recently deployed in Afghanistan, Mali and the Central African Republic.
1506Papal Swiss GuardPope Julius IIThe Pontifical Swiss Guard is one of the oldest active military units presently in existence. They are famous for their last stand which allowed Pope Clement VII to flee from Rome during War of the League of Cognac.
15099th Infantry Regiment “Soria”Ferdinand II of Aragon Kingdom of Naples, Crown of AragonFuerteventura, Canary Islands, SpainFounded in 1509 as "Tercio of Napoli" or "Tercio de Zamudio". It is the second oldest regiment still used for overseas military operations.
1537Honourable Artillery CompanyKing Henry VIII England City of LondonIncorporated by Royal Charter in 1537 by King Henry VIII as the Fraternity or Guild of Artillery of Longbows, Crossbows and Handguns. Fought with distinction in both World Wars. The oldest surviving regiment in the British Army.
15562nd Dragoon RegimentLouis, Prince of Condé Kingdom of France FranceDespite the recent formation of the regiment in its current configuration, it is the oldest French cavalry regiment, dating back to 1556. The French Revolution gave it the designation of the second regiment of dragoons in the French Army, and with brief interruptions it has served under this name in successive French armies ever since. It is the French Army NBC Defense Unit. Still in Service.
1614Guard Hussar Regiment King Christian IV of Denmark Denmark DenmarkUnit amalgamated with and perpetuates Zealand Life Regiment, which was disbanded on 1 January 2001
1636181st Infantry Regiment Massachusetts United StatesPart of the Massachusetts National Guard
1636182nd Infantry Regiment Massachusetts United StatesPart of the Massachusetts National Guard
1642Scots Guards King Charles the FirstRaised in 1642 to form a personal body guard to King Charles I when he campaigned in Ireland; became part of English Army in 1661
1648Danish Artillery RegimentDenmarkDenmarkCurrent formation from 2019; traces origins back to 1648
1650Coldstream GuardsGeorge Monck, 1st Duke of Albemarle Commonwealth of England United KingdomRaised in 1650; became part of the English Army in 1661
1656Grenadier Guards United KingdomSenior Regiment of the Guards Division
1658Royal Life Guards King Frederick III of Denmark Denmark DenmarkBoth a Guard/Ceremonial unit of the Danish Monarch and Infantry Regiment of the Danish Army
16591st Regiment "Granatieri di Sardegna"Duke Carlo Emanuele II di Savoia Savoy ItalyFormed April 18, 1659 as the "Reggimento delle Guardie"
1664Royal MarinesKing James II United KingdomNow roughly small brigade size.
1670Jutland Dragoon RegimentField marshal Ernst Albrecht von Eberstein Denmark Denmark
1670South Carolina State Guard Province of South Carolina South Carolina United StatesFounded in 1670 as the Charleston Militia. Served in Revolutionary War, War with Mexico, Spanish-American War. Later "South Carolina State Defense Force", renamed "South Carolina State Guard".
1684Engineer RegimentChristian V Denmark DenmarkCurrent formation from 1997; traces origins back to 1684
1747111th Infantry RegimentBenjamin Franklin Colony of Pennsylvania Commonwealth of PennsylvaniaThe 111th is the oldest unit in the Pennsylvania National Guard. Today, 1st Battalion, 111th Infantry is part of the 56th Stryker Brigade Combat Team, 28th Infantry Division