The Princes and the Marcher Lords
A successful Welsh prince had many rivals to overcome. Firstly, he had to defeat or buy off his brothers. Then there were his French speaking neighbours: the Marcher lords.
The Marcher lords were land hungry Norman barons. William the Conqueror had created the first ones in 1066-67: Hugh of Avranches, Earl of Chester, Roger Montgomery, Earl of Shrewsbury and William FitzOsbern, Earl of Hereford. Their role was to secure the border and to subdue the Welsh. They had license to grab what they could. Their Norman tenants were even greedier for lands and titles. Together they made the Marches of Wales a wild west.
The Normans had great initial success - reaching as far west as Caernarfon and Aberystwyth. They overstretched themselves, however, and the Welsh princes regained some of their lost lands. By 1100 Wales was divided into "Pura Wallia" ruled by the Welsh princes and "Marchia Wallia" ruled by the Norman barons. The boundary was never fixed, as one side was quick to exploit any weakness shown by the other.
The power of the English king mattered too. Strong kings like Henry I (1100 - 1135) interfered constantly. Civil wars in England, on the other hand, during the reign of Stephen (1135 - 1154) and later under Henry III (1216 - 1272), allowed the Welsh princes the opportunity to strengthen their position. Although in competition, the princes and the Marcher lords would ally against a common rival and a threatened prince would even seek help from the English king. The princes of Powys often sought such help in their struggles with the princes of Gwynedd.
|Pura Walia (independent Wales)|
|Lands gained by Llywelyn in 1234|
|Marchia Wallia (lands rules by the Marcher barons)|