The British Bayonet: A History from Plug to Sword to SA80

Introduction

The bayonet has been a defining weapon of the British soldier for over 350 years. From the earliest plug bayonets of the 17th century to the multi-purpose knife bayonet issued with the SA80 rifle today, the bayonet has evolved alongside changes in firearms, tactics and warfare itself.

Despite repeated predictions of its obsolescence, the bayonet remains in British service — most recently used in combat during the Iraq War in 2004. For collectors, British bayonets represent one of the most varied and rewarding areas of edged-weapons collecting, with examples spanning every major conflict in British military history.

The Plug Bayonet: Origins

The bayonet takes its name from the French city of Bayonne, where, according to tradition, Basque peasants improvised weapons by jamming knives into the muzzles of their muskets in the early 17th century. Whether this origin story is entirely accurate remains debated, but the concept was adopted by European armies from the 1660s onward.

The plug bayonet was a simple dagger with a tapered wooden or bone grip that was pushed directly into the musket’s muzzle. While it converted the musket into a short pike, it had one critical flaw: with the bayonet inserted, the musket could not be fired. This proved disastrous at the Battle of Killiecrankie in 1689, where government troops with plugged muskets were overwhelmed by a Highland charge before they could reload.

The Socket Bayonet: A Revolution in Infantry Tactics

The solution was the socket bayonet, developed in the 1690s. Rather than blocking the muzzle, the socket bayonet attached via a tubular sleeve that fitted over the barrel, secured by a zigzag slot engaging a lug. This allowed the soldier to fire and reload with the bayonet fixed — a transformation in infantry capability.

The socket bayonet became standard British Army issue and remained the primary pattern for over 150 years. The classic Brown Bess socket bayonet of the 18th century — a simple triangular-section blade on a socket — served through the Napoleonic Wars and was produced in vast quantities. These bayonets are commonly found by collectors and represent an affordable entry into 18th-century militaria.

The Sword Bayonet: Victorian Innovation

The mid-19th century brought significant change. The adoption of rifled muskets and then breech-loading rifles made the bayonet’s role as a pike increasingly questionable. In response, the British Army experimented with sword bayonets — long-bladed weapons that could serve both as bayonets and as short swords or machetes.

The Pattern 1853 socket bayonet for the Enfield rifle was the last major socket pattern. It was followed by a series of sword bayonets: the Pattern 1856 and Pattern 1860 for the short rifles issued to sergeants and specialists. The massive Pattern 1907 sword bayonet, with its 17-inch blade, was designed for the Short Magazine Lee-Enfield (SMLE) rifle and became the most iconic British bayonet of the 20th century.

The First World War: Trench Warfare and the Long Bayonet

The Pattern 1907 bayonet entered the First World War as standard issue. Its long blade — designed to give the SMLE an overall length comparable to enemy rifles — made it effective in the close-quarters fighting of trench raids, though its size could be cumbersome in narrow trenches and dugouts.

During the war, a simplified version — the Pattern 1907 (hooked quillon removed) — was introduced in 1913 and became the most commonly issued variant. The original quillon (crossguard hook) was found to snag on equipment and was progressively removed from existing stocks.

The bayonet saw extensive use in trench raids, where soldiers were trained in close-quarters combat. Bayonet fighting became a core element of British infantry training, with dedicated bayonet courses at base camps behind the lines. The psychological impact of a bayonet charge often exceeded its physical effect — many defenders broke and ran before contact was made.

The Second World War: The Spike and the No. 4 Mk II

By 1939, the long sword bayonet was recognised as impractical for modern warfare. The British Army introduced two new patterns for the No. 4 Lee-Enfield rifle:

The No. 4 Mk I spike bayonet — a radical departure from tradition. This was simply a cruciform steel spike with no cutting edge, designed purely for thrusting. Cheap and quick to manufacture, it was issued in enormous quantities and saw service throughout the war and into the 1950s. Spike bayonets are among the most commonly collected British WWII items.

The No. 4 Mk II (Sten) bayonet — a cutting blade version produced later in the war, though the spike remained far more common. The No. 5 Mk I bayonet for the Jungle Carbine featured a shorter Bowie-type blade suited to tropical warfare.

Post-War and Modern Bayonets

The adoption of the L1A1 SLR (Self-Loading Rifle) in 1957 brought a new knife bayonet featuring a Bowie-style blade that could serve as a general-purpose field knife. This pattern served until the 1980s.

The current-issue SA80 bayonet (L3A1) is a multi-purpose knife bayonet that can also function as a wire cutter when combined with its scabbard. It represents the culmination of centuries of bayonet design — a practical tool as much as a weapon. The bayonet was controversially used in a charge by the Argyll and Sutherland Highlanders near Basra in 2004, proving that even in the age of precision weapons, the bayonet retains its psychological and tactical value.

Bayonets as Collector Items

British bayonets are among the most collected edged weapons in the world. The sheer variety of patterns, makers, dates and variations makes them endlessly interesting.

What to Look For

Markings — British bayonets bear a wealth of stamps: government broad arrows, inspector marks, maker names (Wilkinson, Sanderson, Mole), unit stamps and date marks. Learning to read these markings is essential for accurate identification and dating.

Scabbards — a bayonet with its original scabbard is always worth more than the blade alone. Leather, steel and composite scabbards each reflect their era and should match the bayonet pattern.

Condition — original finish, sharp markings and unsharpened blades command the highest prices. Cleaned or polished blades, replacement grips and mismatched scabbards reduce value.

Rare patterns — certain experimental or limited-issue patterns command substantial premiums. The Pattern 1888 Mk I with its unusual crosspiece, Jungle Carbine bayonets and early-issue SA80 bayonets are all actively sought.

Conclusion

From plug to socket to sword to spike to knife, the British bayonet has adapted to every era of warfare while retaining its essential character. It remains the weapon that defines the infantry soldier — and for collectors, it offers a tangible connection to four centuries of British military history. Whether a simple Brown Bess socket or a scarce officer-quality Pattern 1907, every British bayonet has a story to tell.