After the defeat of Llywelyn ap Gruffydd in 1282, Wales was incorporated into England and Edward set about pacifying the new territory.
The Statute divided Wales into the counties of Anglesey, Merioneth, and Caernarvon, introduced the English common law system, and allowed the king to appoint royal officials such as sheriffs, coroners, and bailiffs. Some Welsh customs were allowed to remain, such as the specifics of inheritance, and the Marcher Lords retained most of their independence, as they had prior to the conquest.
The Statute remained in effect until Henry VIII's Act of Union in 1536.