Marcher Lord

A Marcher Lord (Welsh: Barwn y Mers) was a noble appointed by the King of England to guard the border (known as the Welsh Marches) between England and Wales.

A Marcher Lord is the English equivalent of a margrave (in the Holy Roman empire) or a marquis (in France). In this context the word march means a border region or frontier, and is cognate with the verb "to march," both ultimately derived from Proto-Indo-European *mereg-, "edge" or "boundary".

The greatest Marcher Lords included the earls of Chester, Gloucester, Hereford, Pembroke and Shrewsbury (see also English Earls of March).

Some strong earldoms along the Welsh border were granted the privileged status of county palatine shortly after the Norman Conquest, but only that based on Chester survived for a long period.

The term particularly applies to Anglo-Norman lords in Wales, who had complete jurisdiction over their subjects, without recourse to the king of England. The king had jurisdiction only in treason cases, though the lords each bore personal allegiance to the king as feudal subjects.

The Welsh Marches contain Britain's densest concentration of motte-and-bailey castles. After the Norman Conquest, William the Conqueror set out to subdue the Welsh, a process that took a century and was never permanently effective. During those generations the Marches were a frontier society in every sense, and a stamp was set on the region that lasted into the time of the Industrial Revolution. Amid violence and dangers, a chronic lack of manpower afforded opportunities for the intrepid, and the Marcher Lords encouraged immigration from all the Norman-Angevin realms, and encouraged trade from their "fair haven" ports like Cardiff. At the top of this culturally diverse, intensely feudalised and local society, the Marcher barons combined the authority of feudal baron and vassal of the King among their Normans, and of supplanting the traditional tywysog among their conquered Welsh.

...
Wikipedia