But these measures proved inadequate, and in 1533 the lord marcher, Ostafi Daszkiewicz, the hero of Kaniev, which he had successfully defended against a countless host of Turks and Tatars, was consulted by the diet as to the best way of defending the Ukraine permanently against such inroads.
The determination to limit still further the power of the executive was at the bottom of this fatal parsimony, with the inevitable consequence that, while the king and the senate were powerless, every great noble or lord-marcher was free to do what he chose in his own domains, so long as he flattered his "little brothers," the szlachta.
In 1536 it was grouped with a whole series of petty lordships marcher and the lordship of Builth to form the county of Brecknock with Brecon as the county town, and the place for holding the county court.
It was in the successful effort to open this treasure-house that Hamilton's mind received its final temper, " Des-lors it commenga a marcher seul," to use the words of the biographer of another great mathematician.
But the extension of the English borders in South Wales by the conquests of the lords marcher as far as Pembroke and Cardigan.
In 1163 he had completed the conquest of South Wales; the marcher lords were now in possession of the greater part of the land; the surviving Welsh princes did homage for the rest.
When Simon turned the native Welsh prince Llewelyn against the marcher barops, he gave great offence; he was accused of sacrificing Englishmen to a foreign enemy.
For the next two centuries and a half the lands west of Dee and Wye were divided between the new counties, forming the principality of Wales, and the marches where the old feudal franchises continued, till the marcher-lordships gradually fell by forfeiture or marriage to the crown.
Originally he had taken to the hills as a mere outlaw, in consequence of a quarrel with one of the marcher barons; but after many small successes he began to be recognized as a national leader by his countrymen, and proclaimed himself prince of Wales.
The rebel achieved his greatest success in June 1402, when he surprised and routed the whole levy of the marcher lords at Bryn Glas, between Pilleth and Knighton, capturing (among many other prisoners) Sir Edmund Mortimer, the uncle and guardian of the young earl of March, whom all malcontents regarded as the rightful monarch of England.
Brycheiniog was then converted into a lordship marcher and passed to the Fitzwalter, de Breos, the Bohun and the Stafford families in succession, remaining unaffected by the Statute of Rhuddlan (1282), as it formed part of the marches, and not of the principality of Wales.
The lands of the family lay chiefly on the Welsh Marches, and from this date the Bohuns take a foremost place among the Marcher barons.
Towards the end of the 11th century, when the tide of Norman invasion swept upwards along the Wye valley, the district became a lordship marcher annexed to that of Brecknock, but was again severed from it on the death of William de Breos, when his daughter Matilda brought it to her husband, Roger Mortimer of Wigmore.