Robert asked a question on Tuesday that I feel deserved a more thorough answer. See link below:
Olde English PronunciationWikipedia adds (with regards to the specific example of "knight"):
Generally, all letters in Middle English words were pronounced. (Silent letters in Modern English come from pronunciation shifts, which can no longer be reflected by the written form because of fixed spelling constraints imposed by the invention of dictionaries and printing.) Therefore 'knight' was pronounced /ˈknɪçt/ (with a pronounced K and a 'gh' as the 'ch' in German 'Knecht'), not /ˈnaɪt/ as in Modern English.
Also, on the subject of spelling constraints, take a look at some of the European language academies that regulate their languages:Academie Francais
Swedish Academy
Real Academia Espanola
And look at the list of global language regulators...which one stands out as having "no regulator?"
Wikipedia list
Imagine how different (and rigid and less fun) English would be if we had one of these governing bodies telling us exactly how to use our words. Yay for the hodge podge mess of a language that is our mother tongue!