Here's a breakdown:
* The Great Vowel Shift: This major linguistic change in the 14th-18th centuries significantly altered the pronunciation of English vowels. The Western dialect was heavily influenced by this shift, leading to pronunciation patterns that spread throughout the language.
* The London Standard: As London became a center of trade and political power, the dialect spoken there (influenced by the Western dialect) gained prestige. Writers and the upper classes adopted this dialect, further solidifying its importance.
* Printing Press: The invention of the printing press in the 15th century helped standardize spelling and grammar based on the London dialect, making it the dominant form of written English.
* Rise of England: As England became a global power, its language, influenced by the London Standard, spread to other parts of the world.
Therefore, while the Western dialect was a key contributor to modern English, it wasn't the only factor. The standardization process involved a combination of social, political, and linguistic influences.
It's also important to note that modern English isn't just one single dialect. It encompasses a wide range of regional variations, accents, and styles, with the "standard" version often being considered the one used in formal writing and broadcasting.