In what dialect was the original Manuscript of Canterbury Tales written in?

The original manuscript of The Canterbury Tales was written in Middle English.

Specifically, Chaucer used a variety of dialects, but his primary base was the London dialect, which was considered the most prestigious at the time.

However, he also incorporated elements of other dialects, particularly those from the East Midlands and the North, reflecting the diversity of English spoken at the time. This gives his work a rich and vibrant quality, capturing the nuances of different regions.