Seax: History, Types and Sizes of the Early Medieval Knife

A seax is a single-edged iron blade of the early medieval Germanic world, from a large knife with a blade of about 18 cm (7 in) to a “long seax” whose blade can exceed 65 cm (26 in). The word is simply Old English for “knife” (Old Norse sax); archaeologists use it for the big single-edged blades found from the late 5th to the 11th century, first in Frankish and Alamannic graves, later in Anglo-Saxon England, where the angular “broken-back” seax is typical of the 9th to 11th centuries.

This guide sets out what the finds, museum records and medieval texts say: the names, the types with their dates and sizes, the famous seaxes, how they were made and worn, and how far the seax was a Viking weapon. The measurements come from museum records and published studies, listed at the end.

The seax at a glance: quick facts

Question	Short answer
What is it?	A single-edged iron blade with a thick back and a tang for a handle of organic material; from a big knife to a short sword.
Other names	Sax; scramasax (from Gregory of Tours, 6th century); long seax or Langsax for the longest type.
When?	Second half of the 5th century to the 11th century.
Where?	Merovingian cemeteries on the continent (6th–8th centuries), Anglo-Saxon England, and the Viking-Age towns of York and Dublin.
How long?	Blades of about 18–30 cm (short seax), 26–46 cm (broad seax) and 48 to more than 65 cm (long seax).
How was it carried?	In a sheath hung horizontally from the belt.
Best-known example	The Seax of Beagnoth, British Museum 1857,0623.1: 72.1 cm long, inlaid with the Anglo-Saxon runic alphabet.

What is a seax? The word and the object

Seax, sax and scramasax: where the names come from

“‘Seax’ is the generic Old English word for knife,” the British Museum notes, “but is used by archaeologists to describe the larger iron single-edged knives which first appear in Anglo-Saxon graves of the seventh century.” The word existed across the Germanic languages: Old Norse sax, Old High German sahs. Cleasby and Vigfússon’s Icelandic-English Dictionary (1874) defines the Norse word as “a kind of short, heavy sword or sabre” with only one sharp edge, and lists hand-sax, “a short sword, dirk”, and mála-sax, “an inlaid sax”. The name of the Saxons has traditionally been derived from the same word: an old and often repeated idea, not a proven fact. The seax also survives in heraldry: the arms of Essex County Council, granted in 1932, show three seaxes on a red shield, “cutting edges upwards”. They were probably first assigned to the East Saxon kings in the late 16th or early 17th century, long after heraldry began (Essex Record Office).

In Old English the ea was a diphthong, so seax sounded roughly like “sæ-ahks”. Today you will hear “sax”, “see-ax” and “say-ax”.

“Scramasax”, still used in many museums, comes from one sentence. Gregory of Tours, writing in the late 6th century, tells how King Sigibert was murdered in 575, just after his army had raised him on a shield:

Gregory calls them “strong knives” and gives the name as the everyday word. What scrama- means is uncertain, and the compound is not found in Old English. In the 1880s the German archaeologist Ludwig Lindenschmit borrowed the names Sax, Scramasax and Langsax for blades of different sizes, although, as Thomas Koch Waldner notes in a 2019 study (after Böhner), the written sources say nothing about size or use.

Knife or seax? Where archaeologists draw the line

Every seax is a knife, but not every knife is a seax. Heinrich Härke’s study of knives from 47 early Anglo-Saxon cemeteries (Medieval Archaeology, 1989) found blades from 45 to 173 mm, which he sorted, on a sample of 480 knives, into small, medium and “large knives” (130–175 mm), the last “too small to be real weapons”. Above them came the short seax, at about 180 mm, and Kurt Böhner’s narrow seax began at 220 mm. By that yardstick, only one of 128 complete knife blades from the Anglo-Scandinavian (Viking-Age) levels at 16–22 Coppergate in York is a seax (Mould, 2003).

Seax types and dates: narrow, broad, long and broken-back

On the continent: from the narrow seax to the long seax

The classic sequence comes from Merovingian-period cemeteries of the 6th to 8th centuries. Kurt Böhner (1958) divided seaxes into narrow, broad and long; Christiane Neuffer-Müller added the short seax; and Jo Wernard’s study of 785 seaxes from southern Germany (Germania, 1998) refined the types and their dating. The summary below follows Koch Waldner (2019), who applies Wernard’s types to the Alamannic and Bavarian region, warns that the limits vary by a centimeter or two, and stresses that Scandinavia, northern Germany and England developed partly different forms, some later.

• Long narrow seax (second half of the 5th century): slender blades of about 33–46 cm, rare and mostly lavish one-off pieces, “probably special pieces made for persons of higher rank” (Koch Waldner, our translation).
• Short and narrow seaxes (late 5th and 6th centuries): blades of about 18–30 cm and 30–36 cm, often little longer than a knife.
• Light broad seax (late 6th to mid-7th century): about 26–42 cm long and 4–5 cm wide. With it, Koch Waldner writes, the seax begins to change from a thrusting weapon into a cutting one.
• Heavy broad seax (7th century): about 34–46 cm, over 5 cm wide, on tangs almost always longer than 25 cm, still used, he argues, in one hand, leaving the other for a shield.
• Long seax (Langsax, from the last third of the 7th century, typical of the 8th): about 48 to more than 65 cm, but narrower again. Most were one-handed, though some tangs would allow two hands.

In Anglo-Saxon England

Knives turn up in 45 to 50 percent of 5th- to 7th-century Anglo-Saxon burials (Härke), but true seaxes are much rarer. Large knives appear in the 6th century and peak in the 7th and early 8th, which, Härke notes, “is exactly parallel to the frequency curve of seaxes in England”. Once furnished burial ended, later seaxes “tend to be isolated finds, often from rivers, devoid of any associated material, and not susceptible to close dating” (British Museum). That is one reason why so many famous English seaxes come from the Thames.

The broken-back seax

“Broken-back” is the usual name among collectors and reenactors; the archaeological reports used here say “angle-backed”. The back runs straight from the handle, then bends sharply down to the point. The British Museum divides later English seaxes into long narrow blades with the edge almost parallel to the back, like the Seax of Beagnoth, and “a shorter, broader blade with a sharply angled back”, like the Sittingbourne seax; the two “may well have been contemporary, but there is some evidence that the second group is slightly later in date.”

Patrick Ottaway’s study of the ironwork from Coppergate in York (1992) traces the shape. Angle-backs occur on middle Anglo-Saxon seaxes and small knives alike, but blades whose rear part slopes upward before the angle do not seem to appear before the late 8th or 9th century; later examples include the Honey Lane and Sittingbourne seaxes. In Scandinavia such blades are “again rare”, with examples at Birka and Aarhus. At Coppergate itself 34 knives have angle-backs, but none is long enough to count as a seax by Härke’s yardstick (Ottaway; Mould).

How long is a seax? Lengths and dates by type

Type or find	Blade length	Blade width	Date	Source
Long narrow seax (continent)	c. 33–46 cm	2.6–3.2 cm	2nd half of 5th c.	Wernard, via Koch Waldner
Short seax / narrow seax	c. 18–30 / 30–36 cm	2.5–3.5 cm	Late 5th–6th c.	Same
Light broad seax	c. 26–42 cm	4–5 cm	Late 6th–mid-7th c.	Same
Heavy broad seax	c. 34–46 cm	over 5 cm	7th c.	Same
Long seax (Langsax)	c. 48 to over 65 cm	3.8–4.8 cm	Late 7th–8th c.	Same
“Large knife” (England)	13–17.5 cm	2.0–2.7 cm	Mostly 7th–early 8th c.	Härke 1989
Late Anglo-Saxon seaxes and large knives, estimated from their sheaths (England)	generally 17–20 cm; one 25 cm	3–4 cm	About 930 to just after 1066	Mould 2003
Sittingbourne seax (broken-back)	23.1 cm (32.1 overall)	3.5 cm	Early 10th c.	British Museum
Seax of Beagnoth (long seax)	55.1 cm (72.1 overall)	3.9 cm	10th c. (late 9th for Wilson 1964)	British Museum

In inches, a short seax blade runs about 7–12 in, a broad seax about 10–18 in and a long seax 19–26 in or more. The 3- to 5-inch “hand seax” of the old version of this page is an ordinary knife by any of these definitions.

Famous seaxes in museums

The Seax of Beagnoth (the Thames scramasax)

Found in the Thames at Battersea and bought by the British Museum from Henry J. Briggs in 1857, this is probably the best-known seax of all (1857,0623.1, on display in Room 41). It is 721 mm long overall, with a 551 mm blade, weighs 985 grams and is 8.2 mm thick at its thickest point. Both faces are inlaid with copper, brass and silver wire, and one panel carries a 28-letter futhorc, the Anglo-Saxon runic alphabet, and the Old English name Bēagnoþ, “presumably the owner or maker of the seax”. The museum dates it to the 10th century; David Wilson’s 1964 catalog said late 9th.

The British Museum’s record (written in 1984) calls the inscription “the only epigraphical ‘futhorc’ to survive in England”; partial rune-rows are now known on Middle Saxon pins from Brandon, Suffolk, and from Malton, North Yorkshire, so the seax is better described as the only known inscription of the basic 28-letter futhorc in full, even though some of its runes are out of order. The museum also judges it “probably incompetently copied from a manuscript”, and suggests it “may have had a magical or protective function, the significance of which is now lost”. This is the English rune-row, not the Scandinavian one: for the older 24 runes and the 16-rune Younger Futhark of the Vikings, see our Elder Futhark guide.

The Sittingbourne seax: “Biorhtelm made me”

Found while digging house foundations near the Daily Chronicle paper mills at Sittingbourne, Kent (British Museum 1881,0623.1), this is the textbook broken-back seax: 321 mm long, with a 231 mm blade. Panels of silver, brass, copper and niello hold a winged creature, acanthus foliage and two Old English inscriptions: + BIORHTELM ME WORTE, “Biorhtelm made me”, and + S[I]GEBEREHT ME AH, “S[i]gebereht owns me”. The museum dates it to the early 10th century from its decoration, and sees in the maker’s name “the importance and prestige of the weapon-smith in late Anglo-Saxon England”.

Hurbuck, Honey Lane and the Staffordshire Hoard

The Hurbuck seax (British Museum 1912,0723.2) came from a hoard of a sword and tools in a stream bank near Lanchester, County Durham. It measures 71 cm as it survives, fragmentary and much corroded (only the back of the blade is left), and is dated to the 9th or early 10th century, with a slight angle in the back, inlaid grooves, traces of a wooden hilt and a pattern-welded blade. The Honey Lane seax from London was “reputedly associated with coins of Æthelred II dated c.1003” (British Museum).

The Staffordshire Hoard, found near Hammerwich in 2009, is made up of more than 3,500 fragments, most of which appear to come from weapons and war gear, and among them is a seax’s gold hilt: three hilt-collars, a hilt-ring and a miniature pommel with garnet cloisonné, the “seax set” of the British Museum’s scientific report. One collar keeps the impression of a single-edged blade, and scratches suggest the fittings were probably pried off before burial (Blakelock, 2014).

Did Vikings use the seax?

Yes, but it was not a Viking invention. The seax was more than three centuries old when Viking raids began in the late 8th century, and the form now sold as the “Viking seax”, the broken-back, is best documented in England.

What the finds show

• Scandinavia: Ottaway found angle-backed blades rare there, with examples at Birka and Aarhus and the straight-backed variant at Trelleborg and Fyrkat. Single-edged blades are, however, part of the Viking-Age sword finds: in Norway, where about 3,500 Viking-Age swords are known, single-edged blades are most common early in the period, before double-edged ones take over in the 9th and 10th centuries, and they probably developed from the scramasax (Store norske leksikon). The Viking-Age warrior grave Bj 581 at Birka held “a sword, an axe, a spear, armour‐piercing arrows, a battle knife, two shields, and two horses”; its occupant, genetics showed, was a woman (Hedenstierna-Jonson and others, 2017). The paper does not say whether that “battle knife” is a seax.
• York: seven decorated seax sheaths are known from the city, four from the Coppergate excavations, two of them dated by their contexts to 930–975 (Mould, 2003).
• Ireland: Quita Mould reports that, at a recent count, thirteen whole or fragmentary seax sheaths of the 10th and 11th centuries had been found in Dublin, one more than in all of England, plus a possible fragment from Waterford.
• Further afield: similar sheaths turn up in Trondheim, Norway, and Aachen, Germany; Mould suggests their craftsmanship made seaxes and sheaths objects of trade.

In the Viking Age, then, the decorated late Anglo-Saxon seax and its sheath belonged above all to England and to towns such as York and Dublin, where Scandinavian settlers lived among English and Irish neighbors. Who owned them is another matter: the York leather report notes that the apparent merging of Scandinavian and Anglo-Saxon blade designs in the 10th and 11th centuries “prevents attribution to either cultural group on the basis of outline alone”.

The sax in Old Norse poetry and sagas

In Völuspá (stanza 36) a river in the giants’ world pours from the east “through poisoned vales with swords and daggers” (söxum ok sverðum), in Henry Adams Bellows’s 1923 translation, which renders sax as “dagger”; Bellows thought the blades “may represent the icy cold”.

The best-known saga sax is Grettir the Strong’s. In Grettis saga (chapter 18) he robs the burial mound of Kárr the Old and brings back “a short-sword, so good a weapon, that a better, he said, he had never seen” (trans. Magnússon and Morris, 1869), an heirloom of Kárr’s son Þorfinnr, who later gives it to him. Facing the revenant Glámr (chapter 35), Grettir is too spellbound to draw it, then recovers and “drew the short-sword and hewed the head from Glam”. The saga even shows the single edge at work:

Cleasby and Vigfússon cite this passage as proof that the sax “had only one sharp edge”. At Grettir’s death (chapter 82) his killer Öngull strikes his head with the sax and breaks a notch out of its edge, a notch that later betrays Öngull in Constantinople. These are literary scenes: Magnússon and Morris judged the saga the work of a hand later than Sturla Þórðarson, who died in 1284.

How a seax was made

• One edge, a thick back: the blade is wedge-shaped in section, which makes it much stiffer than the double-edged sword (Koch Waldner, after Wernard). The Beagnoth blade is 8.2 mm thick at its thickest, the Sittingbourne blade 6.8 mm.
• Hard edge, soft back: in seven of nine seaxes analyzed from Upper Austria, a hard steel edge was welded to a softer, tougher iron back; all had been quench-hardened, four of them successfully (Koch Waldner).
• Pattern-welding: some blades were forged from strips of different irons to make a visible pattern, “the pinnacle of the smith’s art” (Ottaway), like the Hurbuck seax and a large angle-backed knife from Coppergate.
• Tang and handle: the tang went into a handle of organic material, which rarely survives. Some 7th-century broad seaxes had tangs over 20 cm long.
• Inlay and names: late Anglo-Saxon smiths hammered twisted copper, brass and silver wire into grooves and set panels of niello, and some blades carry personal names, of a maker or an owner, in runes (Beagnoth) or Latin letters (Biorhtelm the maker and Sigebereht the owner).

The seax sheath: worn horizontally at the belt

“The horizontal manner in which seaxes were worn,” writes Quita Mould in the York leather report, “required the seam-edges of sheaths to be reinforced with metal fittings”, for hanging rather than closing them. On the continent the seax hung from the main belt, in a leather sheath riveted along the cutting-edge side, where rows of bronze rivets are found (Koch Waldner); only some great long seaxes of the early 8th century may have hung from a separate sword-belt.

The best evidence comes from waterlogged York. Late Anglo-Saxon seax sheaths are of leather up to 3 mm thick, folded over the back of the blade and closed along the cutting edge with rivets, normally iron, every 40–50 mm, often with stitching too. One Coppergate sheath has iron plates at both ends of the handle part, “presumably to reinforce these two positions for strap attachment”. Before the Norman Conquest, Mould notes, sheaths were suspended from their edges, and the rivets that held the straps run along the cutting-edge side; our inference is that the blade usually sat edge-up. All are “elaborately decorated” with tooled interlace, cross-hatching or acanthus scrolls; Mould dates the English group from about 930 to just after 1066.

The same fashion appears in stone. On a 10th-century cross at Middleton, North Yorkshire, carved with Anglo-Scandinavian ornament, a seated figure in a conical cap wears “a narrow belt from which hangs a horizontal knife in a sheath caught up by a thong to the belt” (Corpus of Anglo-Saxon Stone Sculpture, vol. 3). Scholars disagree on the scene: a pagan warrior in his grave (Binns, 1956) or a lord enthroned (Lang, 1973).

Tool or weapon? What the graves tell us

Both, and the balance shifted with size. The British Museum describes the larger seaxes as “used both as hunting and as fighting weapons”. The cemeteries add a social picture:

• On the continent the seax is the weapon most often found in Merovingian-period graves east of the Rhine. The double-edged sword (spatha) belonged to a small, high-ranking group, but most men of different social levels carried a seax, and from the 6th century it was buried with men into old age and with boys, often as the only weapon in simply furnished graves (Koch Waldner, partly after Frank Siegmund).
• In early Anglo-Saxon England no woman in Härke’s 47 cemeteries had a knife blade longer than 128 mm, and no juvenile one longer than 106 mm. Large knives were “limited entirely to burials of male adults”, a mark of adult male status, increasingly in poorer graves as weapon burial declined.
• Women and knives: knives were found with 61 percent of adult men and 48 percent of adult women. Women carried knives; in these cemeteries the evidence does not show them carrying seaxes. Grave goods, Härke reminds us, were part of a ritual act, not a record of everyday life.

None of the sources used here says the seax was used to build ships, split firewood or, as the old version of this page put it, go “punching through chainmail”. Those are modern guesses, some plausible, none documented.

Seax vs dagger, sword and axe

	Seax	Dagger	Sword (spatha, Viking sword)	Axe
Edges	One, with a thick back	Usually two: a short stabbing blade	Two	One, on a wooden haft
Length	Blade about 18 to 65+ cm	Short	Middle and late Anglo-Saxon blades 63–81 cm (Cameron, cited by Mould); Viking-Age blades 70–90 cm (Store norske leksikon)	Varies
How it hung	Horizontally, in a sheath on the belt	–	In a scabbard, by a strap from the sword-belt	–
Who carried it	Merovingian graves: most men; early Anglo-Saxon graves: large knives with adult men	–	A smaller, wealthier group (Merovingian graves)	Also a working tool

So is a seax a knife, a dagger or a sword? Small ones are knives, long ones short swords, and none is a dagger in the usual sense of a double-edged stabbing blade, even if Bellows rendered sax as “dagger”. For spears, axes, mail and the rest of the kit, see our guide to Viking weapons and armor.

Buying a modern seax: what “historically accurate” means

Modern seaxes range from camp knives loosely inspired by the shape to careful copies of museum pieces. If accuracy matters, ask:

• Which original, and what date? A good reproduction names its model (Sittingbourne, Beagnoth, a Merovingian broad seax) and keeps its proportions. A 10th-century broken-back and a 7th-century broad seax are different things.
• Single edge, thick back, tang: no second edge along the back, and an organic handle on the tang.
• A horizontal sheath: folded leather closed along the edge, fitted to hang across the belt.
• “Viking” in the name: for a kit from Viking-Age York or Dublin, a late Anglo-Saxon-style seax fits; for Scandinavia, the finds point either to an ordinary knife or, early in the Viking Age, to a single-edged sword rather than an English-style seax.

Frequently asked questions

Sources and editorial notes

Rewritten in November 2026. Measurements and dates of named objects follow the holding museum’s online record. English quotations from Gregory of Tours, Völuspá and Grettis saga follow public-domain translations (Brehaut 1916; Bellows 1923; Magnússon and Morris 1869); “our translation” marks our own renderings from Latin, Old Norse or German. Grettis saga chapter numbers follow the Íslendingasögur text on sagadb.org.

• Museum records: British Museum, 1857,0623.1 (Seax of Beagnoth), 1881,0623.1 (Sittingbourne seax), 1912,0723.2 (Hurbuck seax); Corpus of Anglo-Saxon Stone Sculpture, vol. 3, Middleton 2; E. S. Blakelock, Scientific Analysis of the Staffordshire Hoard Seax Set (2014).
• Studies: T. Koch Waldner, “Typologische und technologische Untersuchungen der Saxe aus Überackern”, Archaeologia Austriaca 103 (2019), summarizing J. Wernard, Germania 76 (1998) and K. Böhner (1958); H. Härke, “Knives in early Saxon burials: blade length and age at death”, Medieval Archaeology 33 (1989); P. Ottaway, Anglo-Scandinavian Ironwork from 16–22 Coppergate, The Archaeology of York 17/6 (1992); Q. Mould, I. Carlisle and E. Cameron, Leather and Leatherworking in Anglo-Scandinavian and Medieval York, The Archaeology of York 17/16 (2003); C. Hedenstierna-Jonson and others, “A female Viking warrior confirmed by genomics”, American Journal of Physical Anthropology 164 (2017); H. L. Aannestad, “Sverd – vikingtid”, Store norske leksikon (2026).
• Texts and dictionaries: Gregory of Tours, History of the Franks, trans. E. Brehaut (1916); Historia Francorum IV, Latin text, The Latin Library; The Poetic Edda, trans. H. A. Bellows (1923); Grettis saga, Icelandic text, sagadb.org; The Story of Grettir the Strong, trans. E. Magnússon and W. Morris (1869); R. Cleasby and G. Vigfússon, An Icelandic-English Dictionary (1874); Essex Record Office, “What on earth is a Seax – Essex Day 2023” (2023).