Nom de guerre
Watching the names of the longer lines of my ancestry turn French has been an enlightening experience. I have two more recent French (one a silk-weaver) ancestors who came to colonial Virginia directly from France. So far I have 5 English lines that end up marrying French-named noblewomen, or obtaining a “de” right after the Norman Conquest of England. Three of those lines hail from Cambridgeshire, and two from western Scotland: Ayrshire andpRenfrewshire. Historical accounts of both of the latter lines make them sound purely Scottish, usually in the property grant, but still, the name changes. One of these accounts from 1888 even inserts Marjorie (daughter of Robert the) Bruce in there, but Wikipedia proves that wishful thinking.
I found the following from the first link pretty informative:
Consequences [of the Norman Conquest]
A direct consequence of the invasion was the almost total elimination of the old English aristocracy and the loss of English control over the Catholic Church in England. William systematically dispossessed English landowners and conferred their property on his continental followers. The Domesday Book meticulously documents the impact of this colossal programme of expropriation, revealing that by 1086 only about 5 per cent of land in England south of the Tees was left in English hands. Even this tiny residue was further diminished in the decades that followed, the elimination of native landholding being most complete in southern parts of the country.
Natives were also removed from high governmental and ecclesiastical office. After 1075 all earldoms were held by Normans, and Englishmen were only occasionally appointed as sheriffs. Likewise in the Church, senior English office-holders were either expelled from their positions or kept in place for their lifetimes and replaced by foreigners when they died. By 1096 no bishopric was held by any Englishman, and English abbots became uncommon, especially in the larger monasteries.
Following the conquest, many Anglo-Saxons, including groups of nobles, fled the country for Scotland, Ireland, or Scandinavia. Members of King Harold Godwinson’s family sought refuge in Ireland and used their bases in that country for unsuccessful invasions of England. The largest single exodus occurred in the 1070s, when a group of Anglo-Saxons in a fleet of 235 ships sailed for the Byzantine Empire. The empire became a popular destination for many English nobles and soldiers, as the Byzantines were in need of mercenaries. The English became the predominant element in the elite Varangian Guard, until then a largely Scandinavian unit, from which the emperor’s bodyguard was drawn. Some of the English migrants were settled in Byzantine frontier regions on the Black Sea coast, and established towns with names such as New London and New York.