Background
This harmonisation was done by passing a series of measures between 1536 and 1543. These included:
The first of these Acts was passed by a Parliament that had no representatives from Wales. Its effect was to extend English law into the Marches and provide that Wales had representation in future Parliaments.
The short titles of the Acts were granted by the Statute Law Revision Act 1948.

An Acte for Lawes & Justice to be ministred in Wales in like fourme as it is in this Realme (27 Henry VIII c. 26), passed in 1536 and repealed with effect from 21 December 1993; and
An Acte for certaine Ordinaunces in the Kinges Majesties Domynion and Principalitie of Wales (34 and 35 Henry VIII c. 26), passed in 1543 and repealed with effect from 3 January 1995. The Acts
These Acts also had the following effects on the administration of Wales:
These measures were not unpopular with the Welsh gentry in particular, who recognised that they would give them equality under law with English citizens. The reaction of many of the prominent Welsh of the day and down the centuries were very similar — gratitude that the laws had been introduced and made Wales a peaceful and orderly country.
It was only much later that some of the Welsh started to feel, in the words of A. O. H. Jarman, "that the privileges of citizenship were only given to the Welsh on condition that they forgot their own particular past and personality, denied their Welshness, and merged with England."
Despite historians such as G. R. Elton, who treated the Acts as merely a triumph of Tudor efficiency, modern British and Welsh historians are more likely to investigate evidence of the damaging effects of the Acts on Welsh identity, culture, and economy. While the Welsh gentry embraced the Acts and quickly attempted to merge themselves into English aristocracy, the majority of the population could have found themselves adrift amidst a legal and economic system whose language and focus were unfamiliar to them.

the marcher lordships were abolished as political units and five new counties (Monmouthshire, Brecknockshire, Radnorshire, Montgomeryshire and Denbighshire) were established, thus creating a Wales of 13 counties;
other areas of the lordships were annexed to Shropshire, Herefordshire, Gloucestershire, Glamorgan, Carmarthenshire, Pembrokeshire, Cardiganshire and Merionethshire
the borders of Wales were established and have remained the same since; this was unintentional as Wales was to be incorporated fully into England, but the status of Monmouthshire was still ambiguous until 1974;
the courts of the marcher lordships lost the power to try serious criminal cases;
the office of Justice of the Peace was introduced;
Wales elected members to the English (Westminster) Parliament;
the Council of Wales and the Marches was established on a legal basis;
the Court of Great Sessions were established, a system peculiar to Wales;
a Sheriff was appointed in every county, and other county officers as in England. The Acts and the Welsh language

Union HiJack: an article seeking to explain why Wales is not represented on the Union Flag.