The Middle English had five dialects. They were known as
(i) Northern, (ii) Southern, (iii) East Midland, (iv) West Midland, and (v) Kentish.
The Northumbrian of Old English is now called northen, West-Saxon is now southern and Mercian is divided into two dialects which came to be known as East Midland and west Midland dialect. Kentish remained unchanged.