For hundreds of years after the fall of the Roman Empire, Latin and Greek were used throughout Europe as the languages of education and knowledge. European scholars wrote their works in them and educated men corresponded mostly in Latin, with some Greek, with other educated men of their own or different nationalities.
As late as the end of Queen Elizabeth’s reign, Francis Bacon wrote his scientific works in Latin, although he was one of the most accurate and precise writers of English the English race has ever produced. In fact, the writing of works in Latin and Greek in order to secure an international audience continued up into the eighteenth century.
The fact that Latin and Greek were the languages of the educated accounts for the fact that practically any term we use connected with knowledge or any of the arts, or with religion, science, or education, is of Latin and Greek origin. The terse simple words in English, referring to the home, the family, or the farm are mostly from the Anglo-Saxon, but even here there is an important Latin influence. We must remember that the Romans were in Britain for nearly 400 years and left a strong influence on the local speech, so that the Anglo-Saxons, when they arrived, picked up and incorporated a great many Latin words into their own language.
An everyday Anglo-Saxon-sounding word; such as, plum comes from the Anglo-Saxon pluma; but pluma is merely an Anglo-Saxon mispronunciation of the Latin pruna (plum) from Greek, prounon, a later form of proumnon; which, by the way, comes to us also, through the French, in the form prune.
Again, take the familiar word bishop which is derived from the Anglo-Saxon biscop; but biscop in its turn is only an amputated form of the Latin episcopus (overseer, superintendant), and when we want to form an adjective from bishop we have to go straight to Latin for episcopal; which comes from the Greek word episcopos (watcher, overseer) from the Greek elements, epi- (over) and -scope (watcher, examiner). Many other instances of this kind may be cited indefinitely.
The History of English Was Strongly Influenced by French
Not only did Latin come into English directly and through the medium of Anglo-Saxon, but it came in a copious stream through French. When William the Conqueror defeated the English at Senlac in 1066 and established a Norman aristocracy in England; French became the language of the court and of the landed proprietors and of the upper classes in general, and French was itself a language of almost pure Latin origin. Above all, it must not be forgotten that Latin was the language of churchmen and of the services of the Church from the ninth century to the sixteenth century.
As a result of this continued influence of Latin (as well as Greek elements) from so many directions, the English language is simply saturated with both of these classical sources. In fact, it is fair to say that without some knowledge of the Latin and Greek elements in English, English speakers can not be certain of the accuracy of their spelling or of the correctness of their use of many of the simple and more complex words used in English.