The Semispatha and the Saex

[XorX]

It must be noted that the early "schmale Langsaxe" what means long narrow seax clearly derive from steppe / hunnic weapons of the late 4th. century. There are some finds of them in hunnic contexts in Romania. Their appearence in the rich late-5th-century graves of Pouan, Blucina, Tournai IMO is part of the widespread use of a general eastern clothing and weapons style of the germanic "nobility" which includes cloisonnée stuff, gold spatha hilts etc.
Finds of schmale Langsaxe are really rare in normal lower status warrior graves between Romania and France. I know of three or so: one quite late example in Westheim / Bavaria (~530) and two mentioned in the Westheim publication from Thuringia.
The typical merovingian (better: central european) sax is a developement from "big knives": early examples ("Schmalsax" = narrow seax) from ca. 500-580 normally are much shorter than the Pouan /Blucina/.pieces and normally have less elaborate handles and fittings. They are followed by the "breitsax" or broad seax (~580-630), longer and heavier, the "schwerer Breitsax" or heavy broad seax (~630-680) and finally by the "Langsax" or long seax (~680-~800) which confusingly has nearly the same name as the early pieces, but is a weapon of another ancestry and much bigger dimension (up to 85cm in length). This is the type of weapon mentioned in the carolingian sources as semispatum.
I don`t really know about the chronology of seaxes on the British Isles, but, as far as I know, there are neither "big knives" which could be classified as seax in the 4th and 5th century saxon graves on the continent (for example the really rich grave with the "throne" from the Fallward near Bremerhafen from ~400-450 which contains a spatha, elaborate late roman pelt plates,...; but no "seax") nor in the early graves in Britain. The seax seems to appear in the 6th century in these regions as a mass "weapon" or better tool ( as it did on the continent).