Geoffrey Chaucer first read his "The Canterbury Tales" to the royal court on August 17 in 1397.
The Middle English collection of 24 stories (which totals over 17,000 lines!) follows the journey of a group of pilgrims traveling from London to Canterbury. Each pilgrim was meant to tell a total of four stories, however it is generally believed that Chaucer did not complete the writing. In any case, this work is considered to be among the most important pieces of English literature.
Chaucer was given the honor of reading his tales to the court and essentially popularized the use of the English language across the kingdom. Anglo-Norman French (and Latin to a lesser degree) were more common at the time. King Henry IV became the first king to take the Coronation Oath in English in 1399, and French became a secondary language.
There are no surviving manuscripts by Chaucer - the image here is thought to be of a page written down by scribe Adam Pinkhurst, circa 1400.