Soon after the departure of the Roman legions in 410 CE, the invading Anglo Saxons who established the Kingdom of Mercia under King Penda came up against the adjoining Welsh Kingdoms, at first as neighbours but later as enemies when his successors moved into the modern counties of Cheshire, Shropshire and Herefordshire, which were to become known as the Welsh Marches.
During his reign King Offa constructed the now famous earthworks said to stretch from sea to sea, although excavation has failed to find all of it. This has since that date become the accepted border between England and Wales.
To support and defend the border, following the Norman conquest, the Earldoms of Chester, Shrewsbury and Hereford were established, which were to become the administrative towns of the three areas first named in the Domesday Book as the Welsh Marches. Despite all these defensive measures there followed centuries of raiding between the two countries. The enormity of this task was recognised by the fact that the areas were independent of the crown and self governing, creating a wild frontier state.
By the 12th century the March had expanded as the Norman Barons seized two thirds of all Welsh lands to the east and along the south coast. Edward I followed this up with full scale invasion in the 1280s, and to secure and control the areas hundreds of large and small castles were built many of which can still be seen. Migration into the area of Norman and English settlers was also encouraged, and new towns were established like Ludlow, Chepstow and Monmouth to facilitate trade in the area.
Edward was renowned for his law making, and following his conquest of the principality he, Edward Longshanks, soon to earn the title Hammer of the Scots, drew up the Statute of Rhuddlan. He set up several more Marcher Earldoms as shire counties, and held lordship over Welsh lands from those nobles who had surrendered to his terms.
All the tooing and froing however came to an abrupt end following the defeat of Richard III by Henry Tudor at Bosworth Field in 1485 during the Wars of the Roses. He was to become the first to provide a Welsh monarch for the English throne, making his fated son Arthur Prince of Wales. More than a crown was lost at Bosworth, the premature death of Arthur was to trigger centuries of religious turmoil, torture and death.
The Marcher Earldoms were considered superfluous at that time as they created a no mans land between the two areas where the law of the land could be avoided, so the Marcher Earldoms ceased to be during the reign of Henry VIII in 1536 when the two countries became united.
The new regulations saw some Welsh border areas moved under English Lords and the government of Wales and the areas of the Welsh Marches administered from Ludlow Castle until 1689 when William of Orange came to power.