How did Anglo-Norman writing and spelling affect the development of Middle English?

The Norman Conquest of 1066 significantly altered the development of Middle English, particularly through the influence of Norman scribes who introduced new writing and spelling conventions.1

Following the conquest, the English writing system shifted from the traditional insular hand to the Carolingian script used on the Continent. This transition brought about several lasting changes to English spelling:1

• Vowel Representation: Scribes replaced Old English characters and spellings with French-influenced forms. For example, Old English y became u, ū became ou (or ow when final), and ȳ became ui. To improve legibility, u was often written as o near letters like m, n, and v (e.g., sunu became sone).1
• Consonant Clusters: Many Old English consonant combinations were modified to align with French orthography. Old English cw became qu, hw became wh, ċ became ch or tch, sċ became sh, and -ht became ght (e.g., miht became might).1

These changes were not merely aesthetic; they reflected the broader linguistic shift as French became the language of administration and law, eventually leading to a trilingual environment in England where English, French, and Latin coexisted for centuries.21