What Is a Broken-Back Seax? The Late Anglo-Saxon Blade

A broken-back seax is a single-edged Anglo-Saxon blade whose spine runs dead straight from the handle and then "breaks" in one sharp downward angle to meet the point, while the cutting edge stays straight the whole way. The form appears in England in the 9th and 10th centuries and is the most instantly recognisable silhouette in the whole seax family.

Nothing else from the early medieval world looks like it. Most knives of the period taper in a curve; the broken-back angles, once, decisively, as if someone had snapped the spine over a knee. It is the shape that makes a seax identifiable in a museum case from ten feet away, and it belongs almost entirely to England in the thick of the Viking Age.

What is a broken-back seax?

Structurally it is a seax like any other: one sharpened edge, a thick unsharpened spine, a full or near-full tang, a grip of wood, horn, bone or antler, and no meaningful crossguard. If you want that wider family explained from the ground up, start with our guide to what a seax is.

What sets the broken-back apart is purely the profile. Picture the blade in side view. The edge runs in a straight line from the handle to the tip. The spine also runs straight (parallel or nearly so) for roughly two thirds of the blade's length. Then it stops running straight and drops, in a single clean angle of somewhere between 20 and 45 degrees, down to meet the edge at the point.

That is the whole definition. Not the length, not the width, not the decoration, just that one angle. Broken-back seaxes survive as small belt knives and as langseaxes over 70 cm long, and both count.

Where the name comes from

"Broken-back" is a modern archaeological label, not an Old English one. Nobody in the 10th century called it that. It was coined by later scholars describing exactly what the eye sees: a back (the spine) that appears broken.

You will also see the same form called an angle-back seax or a bent-back seax in the literature, and occasionally just "the Anglo-Saxon type." All four terms describe the same silhouette. If a seller uses them interchangeably, that is normal and not a red flag.

The spelling wanders too. Written as two words it is a broken back seax, listings often stretch it to broken back seax knife, and the most common misspelling drops a syllable to brokeback seax. They all mean this blade.

When and where it was used

The broken-back is a late form. Earlier seaxes (the narrow and broad types of the 6th to 8th centuries) generally have spines that curve gently or run straight to a drawn-out point. The angled spine turns up in England from roughly the 9th century and runs through the 10th, with some examples reaching into the 11th.

That dating puts it squarely in the Viking Age, in the period of Scandinavian raiding and then settlement in the Danelaw. The form is overwhelmingly an English one: the great concentration of finds comes from England, and a striking number were dredged out of the River Thames, where blades seem to have been deposited or lost in quantity.

It is worth being precise about the Norse connection, because shops routinely overstate it. The broken-back seax is an Anglo-Saxon form that was in use while Vikings were in England, not a Scandinavian design the Norse brought with them. Norse warriors in England would certainly have encountered and carried them. That is a real connection, and it is enough. It does not need inflating.

Broken-back vs the earlier seax forms

Set a broken-back beside a narrow seax from three centuries earlier and the difference is not subtle.

The narrow seax is slim, long in proportion to its width, and its spine flows to the tip without interruption. It reads as a knife. The broad seax is heavier and wider in section, still without the angle. The broken-back puts a hard geometric break into the outline, and the result reads less like a knife and more like a deliberate weapon shape.

The other thing that separates late broken-back blades is decoration. Many carry deep grooves (fullers) cut along the flat parallel to the spine, and on the better pieces those grooves and the surrounding steel are inlaid with wire in silver, brass or copper alloy. The most famous surviving broken-back langseax, the Seax of Beagnoth in the British Museum, has an entire runic alphabet inlaid this way.

Why the angled spine works

The honest starting point is that we do not know for certain why smiths adopted the shape, and anyone who tells you otherwise is guessing with confidence. But several practical consequences follow from the geometry, and they are worth knowing.

The angle drives the point down toward the centreline of the blade rather than leaving it high on the spine. That puts the tip more directly behind a thrust. It also concentrates mass in the forward half of the blade while keeping the spine thick right up to where the angle starts, which helps a chopping cut. And because the edge stays perfectly straight, the blade is easy to sharpen on a flat stone and excellent for the draw cuts that dominate everyday work: skinning, slicing, trimming leather.

There is also the simple fact that it is a distinctive shape in a period when weapon fashion mattered. Aesthetics are not a lesser explanation than mechanics.

Buying a broken-back seax today

Four things separate a good reproduction from a costume prop.

The angle should be crisp. A real broken-back has one clean change of direction, not a soft curve pretending to be an angle. If the spine rounds off gradually, it is a clip-point knife with marketing.

The spine should be thick and flat. Unsharpened, square-shouldered, and substantial. You should be able to rest a thumb on it comfortably. A false edge ground into the angled section is a modern tactical-knife habit and is wrong for the form.

The tang should be full or near-full. Originals ran the steel deep into the handle. A short stub tang glued into a grip is a wall-hanger.

The sheath should be horizontal. Seaxes were carried across the front of the belt, edge up, in a sheath riveted along its length and hung from loops, not vertically on the hip. A maker who gets the sheath right has usually understood the rest.

Our hand-forged pieces are in the Viking seax and Viking-styled knife collection: carbon and stainless blades, carved hardwood handles, genuine leather sheaths.

Keep exploring: the full background in what a seax is, how the largest seaxes cross into short-sword territory in seax, sword and dagger, or the separate Norse form in our guide to the Viking dagger, then browse the seax collection.

Broken-back seax FAQ

What is a broken-back seax?

A single-edged Anglo-Saxon blade whose spine runs straight from the handle and then drops in one sharp angle to meet the point, while the cutting edge stays straight throughout. The name describes that profile, not the blade's length: broken-back seaxes range from small belt knives to langseaxes over 70 cm.

When was the broken-back seax used?

Mainly in England during the 9th and 10th centuries, with some examples running into the 11th. That places it in the Viking Age, during Scandinavian raiding and settlement, though the form itself is Anglo-Saxon rather than Scandinavian.

Is a broken-back seax a Viking weapon?

It is an Anglo-Saxon design that was in use while Vikings were active in England, so Norse warriors there would have encountered and carried them. It was not a Scandinavian form the Vikings brought with them, and sellers who claim otherwise are overstating the link.

Why does the spine angle down?

We do not know for certain. The geometry does bring the point down toward the blade's centreline, which puts the tip more directly behind a thrust, and it concentrates mass forward for chopping while leaving a straight edge that is easy to sharpen. Fashion may also have played a part.

What is the most famous broken-back seax?

The Seax of Beagnoth in the British Museum, a 72 cm langseax dredged from the Thames at Battersea in 1857, carrying wire-inlaid runes including the only known complete Anglo-Saxon futhorc inscription.