The origin of the verb to die is a bit of a mystery. One would expect that such a basic verb would go back to Old English, especially since the word has a Germanic root. But it is not attested to the Old English literature, not appearing until the early Middle English period. Instead, Old English used two other verbs, sweltan (which survives in the modern sweltering) and steorfan (the modern form of which is to starve, although in Old English it could mean death by any means, not just lack of food).
The standard interpretation is that word disappeared early in the Old English period, only to be reintroduced by the Normans. It comes from an Old Norse root deyja. The verb also died out in Gothic and the other West Germanic languages too, surviving only in the North Germanic languages.
Its first appearance is post-Conquest in a c.1135 manuscript The History of the Rood-Tree:
Forþan ðe ic nu degen sceal
(Because I now shall die)
(Note the Old English letter G could have a / y / sound, so degen would be pronounced / die-yen /.)
The date, relatively shortly after the Norman Conquest, and the Anglo-Saxon language surrounding it, however, indicate that the word may not have been brought to England by the Normans. It’s possible, and perhaps even probable, that the verb survived in dialectal use and simply was not recorded in the extant manuscripts until after the conquest.
This is supported by the fact that both the noun death and the adjective dead are well attested in Old English. And the form was dead is a frequently used way to express to die in Old English.
From Beowulf, lines 467-48:
ða wæs Heregar dead
min yldra mæg.
(then was Heregar dead
my older brother)
The noun form can be found in The Blickling Homilies from c.971:
He mid his costunge ure costunge oforswiþde and mid his deaþe urne deaþ.
(He overcame, with his tribulation, our tribulation, and with his death, our death.)
(Source: Oxford English Dictionary, 2nd Edition)
Copyright 1997-2015, by David Wilton