During a policy session in Zaandam with some Dutch, UK, Spanish and US peers we had a moment when our Dutch hosts had an excited conversation in Dutch but since it was a tech conversation both myself and the UK member blurted out at the same time that our Dutch must be getting better because we understood most of what they just said and didn't need them to translate it for us.
Latin was the first official language in the UK, back when Celtic and Brythonic language was widespread.
The Normans were in the UK, viking there way up our rivers and establishing the Danegeld before Normandy was Normandy and, well, before French was French.
Old French was Gallo-Romance and Middle French, AIUI, emerged with the Norse influence as the Scandinavians moved down past Britain and into Europe. Modern French, ie French, came long after the English court took on the language of the Normans (1066, and all that).
Out of this melange English was born, the next official language of England famously legislated as such by the Welsh-speaking Henry Tudor in the late C.15th.