Wales had retained a separate legal and administrative system, which had been established by Edward I in the late 13th century. Under the Tudor monarchy, Henry VIII replaced the laws of Wales with those of England (under the Laws in Wales Acts 1535–1542).
Wales now ceased to be a personal fiefdom divided between the Prince of Wales and the Earl of March, and was instead annexed to the Kingdom of England, and henceforth was represented in the Parliament of England.
During the 1530s, Henry VIII overthrew the power of the Roman Catholic Church within the kingdom, replacing the pope as head of the English church and seizing the church's lands, thereby facilitating the creation of a new Protestant religion. This had the effect of aligning England with Scotland, which also gradually adopted a Protestant religion, whereas the most important continental powers, France and Spain, remained Roman Catholic.
In 1541, during Henry VIII's reign, the Parliament of Ireland proclaimed him king of Ireland, thereby bringing the Kingdom of Ireland into personal union with the Kingdom of England.
Calais, the last remaining continental possession of the Kingdom, was lost in 1558, during the reign of Philip and Mary I.
Their successor, Elizabeth I, consolidated the new Protestant Church of England. She also began to build up the Kingdom's naval strength, on the foundations Henry VIII had laid down. In 1588, her new navy was strong enough to defeat the Spanish Armada, which had sought to invade England in order to put a Catholic monarch on the throne in her place.
The House of Tudor ended with the death of Elizabeth I on 24 March 1603. James I ascended the throne of England and brought it into personal union with the Kingdom of Scotland. Despite the Union of the Crowns, the kingdoms remained separate and independent states: a state of affairs which lasted for more than a century.
The Stuart kings overestimated the power of the English monarchy, and were cast down by Parliament in 1645 and 1688. In the first instance, Charles I's introduction of new forms of taxation in defiance of Parliament led to the English Civil War (1641–45), in which the king was defeated, and to the abolition of the monarchy under Oliver Cromwell during the interregnum of 1649–1660. Henceforth, the monarch could reign only at the will of Parliament.
Following the Restoration of the monarchy in 1660, an attempt by James II to reintroduce Roman Catholicism—a century after its suppression by the Tudors—led to the Glorious Revolution of 1688, in which he was deposed by Parliament. The Crown was then offered by Parliament to James II's Protestant daughter and son-in-law/nephew, William III and Mary II.
In 1707, Acts of Union were passed by both Parliament of Scotland and the Parliament of England, to ratify the 1706 Treaty of Union, and bring into being the new Kingdom of Great Britain. Anne, the last monarch of the House of Stuart, became the first monarch of the new kingdom. The English and Scottish Parliaments were merged into the Parliament of Great Britain, located in Westminster, London.
At this point England ceased to exist as a separate political entity, and since then has had no national government. The laws of England were unaffected, with the legal jurisdiction continuing to be that of England and Wales, while Scotland continued to have its own laws and law courts.
This continued after the Act of Union of 1800 between the Kingdom of Great Britain and the Kingdom of Ireland, which created the United Kingdom of Great Britain and Ireland (later the United Kingdom of Great Britain and Northern Ireland).(wikipedia.org)