"bubonic/pneumonic plague epidemic of 1347-51 in Europe," a modern name, introduced in English 1823 by Elizabeth Penrose's history of England. The contemporary 14c. name for it in most European languages was something like "the great dying" or simply "the plague;" in English it was the pestilence (or, looking back after its return in 1361-2, the first pestilence).
The term "Black Death" first turns up in 16c. Swedish and Danish chronicles, but it is used in reference to a visitation of plague in Iceland (which had been spared in the earlier outbreaks) in 1402-3 that carried off much of the population there. The exact sense of "black" is not clear. The term appears in English translations of the Scandinavian works from 1750s. It was picked up in German c. 1770 and applied to the earlier outbreak and was taken from there into English in that sense.
"the people of England; the speech of England," noun use of Old English adjective Englisc (contrasted to Denisc, Frencisce, etc.), "of or pertaining to the Angles," from Engle (plural) "the Angles," the name of one of the Germanic groups that overran the island 5c., supposedly so-called because Angul, the land they inhabited on the Jutland coast, was shaped like a fish hook (see angle (n.)). The use of the word in Middle English was reinforced by Anglo-French Engleis. Cognates: Dutch Engelsch, German Englisch, Danish Engelsk, French Anglais (Old French Engelsche), Spanish Inglés, Italian Inglese.
Technically "of the Angles," but Englisc also was used from earliest times without distinction for all the Germanic invaders — Angles, Saxon, Jutes (Bede's gens Anglorum) — and applied to their group of related languages by Alfred the Great. "The name English for the language is thus older than the name England for the country" [OED]. After 1066, it specifically meant the native population of England (as distinguished from Normans and French occupiers), a distinction which lasted about a generation. But as late as Robert of Gloucester's "Chronicle" (c. 1300) it still could retain a sense of "Anglian" and be distinguished from "Saxon" ("Þe englisse in þe norþ half, þe saxons bi souþe").
... when Scots & others are likely to be within earshot, Britain & British should be inserted as tokens, but no more, of what is really meant [Fowler]
In pronunciation, "En-" has become "In-," perhaps through the frequency of -ing- words and the relative rarity of -e- before -ng- in the modern language. A form Inglis is attested from 14c. and persisted in Scotland and northern England, and Ingland and Yngelond were used for "England" in Middle English, but the older spelling has stood fast. Meaning "English language or literature as a subject at school" is from 1889.