'anglais' originates from Old French, specifically the word 'angelés'/'englois', where the root refers to the Angles, a Germanic people whose name gave rise to 'England'.

'anglais' changed from Old French forms like 'englois'/'angleis' and was influenced by Latin references to the 'Angli' (the Angles); it eventually became the modern French word 'anglais'.

Initially it referred to the people called the Angles (and thus to people from that region); over time it came to mean broadly 'of or relating to England' and also 'the English language'.