The History of Vowel Changes in the Chinese Language

The population of london in the year 15 hundred was about 75 thousand people. A century later, it had tripled to over 200 thousand people. With people pouring into cities like london from country side, there was suddenly a great mixture of dialects. There may have also been social factors at work, like the preference for one particular dialect or manner of speech among several competing options. At any rate, by the end of that period, a new system of vowel pronunciation had emerged.