Abstract The aim of the article is to discuss the legal language transformations from a diachronic perspective taking into account the following factors: (i) spatial and temporal, (ii) linguistic norm changes, (iii) political, (iv) social (customs), and (v) globalization as well as (vi) EU-induced. Spatial and temporal factors include legal relations influenced by climate and the cycles of nature. Linguistic factors include spelling reforms and grammatical changes each language undergoes, for example, as a result of usage. As far as the law is concerned, normative changes can be observed when laws are amended. Other factors such as customs, usage, etc. cannot be neglected when discussing the language of the law. Analogously political correctness and usage can be observed in gender sensitive language and the introduction of such terms as chairperson instead of chairman. Social factors should not be overlooked. As a result of social changes, numerous terms have been introduced to legal lexicons in many countries starting with same-sex unions or same-sex-marriages. The so-called political correctness enforces some language changes and leads to the introduction of new terms and at the same time the abandonment of others. Consequently, some terms cease to be used and consequently become archaic. The aim of the article is to focus on diachronic changes in legal languages and present the communication problems resulting from them from intra- and inter-lingual perspectives.