(ii) The Midland group of dialects was in use in the area demarcated by the river Humber in the north and the river Thames in the south. This extensive group of dialects is further sub-divided into four dialects known as the north Midland dialect, the south Midland dialect, the east Midland dialect and the west Midland dialect.
(iii) The southern group of dialects was in use in the south of England with the river Thames being the northern boundary of the area of its use. This group is further subdivided into two dialects, the south-eastern dialect and the south-western dialect. The south-eastern dialect is also known as the Kentish dialect.
During the Old English period, West Saxon, the Old English ancestor of the south-western dialect of Middle English, was the most influential of all the dialects. It was the dialect spoken in and around the capital of the West Saxon kingdom, i.e., the dialect spoken by King Alfred the Great, who is rightly considered to be one of the most important founders of English prose.
One of the best proofs of the dominance of West Saxon over the other dialects of Old English lies in the fact that the manuscripts of the important literary texts of that period are available only in this dialect. It is possible that some of these Old English literary texts were originally written in some other dialects but later rendered into this dialect.
During the Middle English period, however, the sphere of influence moved from the south western region of England to the Midland region and the east Midland dialect (also known as London English) emerged as the most influential of all the Middle English dialects and gained acceptability all over England as the standard medium for written communication and more importantly as the standard medium for literary writings.