Welsh Marches, lands in Wales along the English border. After the Norman conquest of England in the 11th cent., William I established the border earldoms of Chester, Shrewsbury, and Hereford to protect his English kingdom. Norman barons were encouraged by William's successors to conquer and hold other earldoms in the east of Wales. These nobles ruled as petty feudal princes, owing allegiance only to the king. Attempts to control the resulting lawlessness were made by Edward I and by Edward IV, who set up the Council of Wales and the Marches in 1471. Finally the act of Union (1536) abolished the more than 100 marcher lordships, providing for their division into Welsh shires or their incorporation into English counties.