To the outside observer, the English language must appear impossibly complex. Unlike the strict morphology and syntax of Spanish, Italian, or Japanese, English is a labyrinthine trip into strange etymological dead-ends, seemingly random rules of pronunciation, and enough homonyms to leave even the most accomplished ESL student scratching their head. The reason for English's everything-but-the-kitchen-sink approach is tied inexorably to its history, and nowhere is that more apparent than in the Norman Conquest of 1066 AD, an event that rewrote the English book from top to bottom.
Even before William of Normandy set his sights on the English throne, the isles which we now know as Britain were in a constant state of identity crisis. Centuries of invasions from the Celts, the Welsh, the Angles, the Saxons, and finally the Danes had left the isles culturally and linguistically schizophrenic, and yet William the Bastard's invasion still represents a total shift from what came before it; a lingual modernism at the edge of a sword. This is immediately evident in comparing the opening lines of the two most famous English works of the time, Beowulf, written around the 8th century AD, and The Canterbury Tales, from the 14th. Beowulf's opening lines are incomprehensible to the modern layperson, in a language that looks more German or Scandinavian than English, which betrays the Saxons and Danes Germanic presence: “Hwæt, we gardena in geardagum/þeodcyninga þrym gefrunon/hu ða æþelingas ellen fremedon!” (Anonymous 1) Despite this, in just a few hundred years Chaucer's Canterbury Tales offers us a piece that is recognizably English to the modern eye, if old-fashioned: “Whan that aprill with his shoures soote/The droghte of march hath perced to the roote/And bathed every veyne in swich licour/Of which vertu engendred is the flour” (Chaucer 1). 700 years is a long time, to be sure, but it's almost too quick for a language to completely change, as English did, and the proof is in the change of the ruling class when William gave positions to all his French-Norman followers and ousted the Anglo-Saxon elite the deposed House of Wessex supported. English became inundated with French language conventions, from the previously-unused sibilant C, to the new distinction between the Anglo-Saxon-derived words 'cow' and 'pig' (since the Saxon lower-class were the farmhands) and the French-derived words 'beef' and 'pork' (since the French nobility were the ones doing the eating). The Norman conquest also put the wheels in motion for another significant linguistic shift some time later; English tongues attempted to make sense of foreign French accents and pronunciations, which led to the eventual effect of the so-called Great Vowel Shift, where vowels were moved up further in the mouth, playing more off of the lips and blade of the tongue than the soft palate in Saxon and early post-Conquest language. The effect was startling; Chaucer's 'hu' (pronounced 'hoo') became Shakespeare's 'how' and words began to become more expressive with the whole of the mouth opened to their pronunciation.
So here we are, a thousand years removed from William of Normandy striking down the last Saxon king on the fields of Hastings and 700 years removed from The Canterbury Tales, and modern English is still rooted in what Chaucer spoke and wrote, whereas the Old English of the Anglo-Saxons is all but dead and gone. Of course imperialism will alter a language and a culture, but much like the way the Normans Norse lineage differentiated them from the French, so did the Normans blend with the Anglo-Saxons and create an uniquely English people with a identity removed from their conquerors. Whether it initially seemed good or ill, the conquest of England by the cosmopolitan French thrust the island's inhabitants out of the Dark Ages, and its appropriation of French and Latin linguistic practices was but one part of its modernization that allowed Britain to become truly Great.
Al Shamari, A. (n.d.). The Influence of the Norman Conquest on English. Iraqi Academic Science Journals.
Chaucer, G., & Coghill, N. (2003). The General Prologue. In The Canterbury Tales (p. 1). London: Penguin Books.
Heaney, S. (2001). Beowulf: A new verse translation (p. 1). New York: W.W. Norton &.
Loyn, H. (1980, April). The Norman Conquest of the English Language. History Today.