When the French-speaking Normans conquered England and became its ruling class, they brought their speech with them, adding a massive amount  of French and Latin vocabulary to the English language  previously spoken there.
Les Normands francophones envahirent l'Angleterre et prirent le pouvoir, important leur langue avec eux. Ainsi, énormément de mots  français et latins intégrèrent l'anglais parlé avant l'invasion.