Norman Invasion of Wales

The Norman invasion of Wales began shortly after the Norman conquest of England under William the Conqueror, who believed England to be his birthright. It was not William's intention to also invade Wales, but Welsh attacks under King Gruffudd ap Llywelyn, uniter of Wales, against the Normans in England, beginning in the years prior to the main Norman invasion in 1066, eventually forced William's hand. Initially (1067–1081), the invasion of Wales was not undertaken with the fervor and intentionality of the invasion of England. However, a much stronger Norman invasion began in 1081 and by 1094 most of Wales was under the control of William's eldest son, King William II of England. The Welsh greatly disliked the "gratuitously cruel" Normans and by 1101 had regained control of the greater part of their country under the long reign of King Gruffydd ap Cynan, who had been imprisoned by the Normans for twelve years before his escape. Gruffydd had some indirect help from King Magnus III of Norway (Magnus Barefoot) who attacked the Normans briefly off the Isle of Anglesey in Northwest Wales near Ynys Seiriol, killing Hugh of Montgomery, 2nd Earl of Shrewsbury and leaving the Normans depleted and demoralized. Magnus went on to take the Orkney Islands, the Hebrides, and the Isle of Man, islands north of Wales and west or north of Scotland and England, in 1098.

Under William's fourth son, King Henry I of England, the Normans, now well established in England, responded by pushing west into Wales. This time, both the Welsh and the Normans were more interested in making peace than fighting bloody battles, and a relatively stable situation developed, although the Normans fared more poorly in southeast Wales than in the west of the country. The standoff continued from 1135 to 1154 under Stephen, King of the English, nephew of Henry and a maternal grandson of William, who became locked in a power struggle and civil war with Empress Matilda, Henry's daughter and only surviving legitimate child.

In 1157, King Henry II of England, son of Matilda, led his first, relatively successful, expedition into Wales, beginning a stronger display of English/Norman power. In 1163 Henry displayed even greater might, and the two most powerful Welsh princes, Rhys ap Gruffydd and Owain Gwynedd, soon accepted the situation and paid homage to Henry, beginning a period of the domination of Wales by England but with a degree of independence by the Welsh, a situation which has continued, to various extents, to the present day.