Lots of languages are hybridized from multiple, overlapping waves of conquerers, "but English’s hybridity is high on the scale compared with most European languages," which gives us a realm of weird pronunciations, weirder spellings, inconsistent grammar, and a near-unique situation whereby speakers of languages that are close cousins to English can more-or-less understand English, too. The amalgam of inconsistently blended Celtic, Norse, French and Latin make English a nightmare to learn, speak and spell -- which makes the language's success in the world something of a miracle. As long as the invaders got their meaning across, that was fine.