The paper attempts to provide a brief outline of the historical development of Legal English. Among other things, Legal English is characterised by numerous borrowings from other languages and it is therefore important to study its historical development and trace the origins of the words and phrases that are commonly used today. From the ninth century until the twelfth, words were mainly borrowed from Scandinavian languages. However, language of common law was constructed after the Norman Conquest in 1066. The written language of the law after the Conquest was Latin, as in most of Europe, but French became the language of the law courts in England, and French loans were concerned with law and administration. Thus for more than 300 years the English legal profession was trilingual, as Latin was used for legal records, English for hearing witnesses and French for oral pleadings. The traces of that period which are still present in modern Legal English are explored in the paper, as a better insight into the historical development of Legal English enables a better understanding of the ways in which it is still changing today.