Henry VIII (28 June 1491 28 January 1547) was King of England from 22 April 1509 until his death in 1547. Henry is best known for his six marriages, and for his efforts to have his first marriage (to Catherine of Aragon) annulled. His disagreement with Pope Clement VII about such an annulment led Henry to initiate the English Reformation, separating the Church of England from papal authority. He appointed himself Supreme Head of the Church of England and dissolved convents and monasteries, for which he was excommunicated. Henry is also known as "the father of the Royal Navy", as he invested heavily in the navy, increasing its size from a few to more than 50 ships, and established the Navy Board.Domestically, Henry is known for his radical changes to the English Constitution, ushering in the theory of the divine right of kings in opposition to Papal supremacy. He also greatly expanded royal power during his reign. He frequently used charges of treason and heresy to quell dissent, and those accused were often executed without a formal trial by means of bills of attainder. He achieved many of his political aims through the work of his chief ministers, some of whom were banished or executed when they fell out of his favour. Thomas Wolsey, Thomas More, Thomas Cromwell, Richard Rich, and Thomas Cranmer all figured prominently in his administration.

Henry was an extravagant spender, using the proceeds from the dissolution of the monasteries and acts of the Reformation Parliament. He also converted the money that was formerly paid to Rome into royal revenue. Despite the money from these sources, he was continually on the verge of financial ruin due to his personal extravagance, as well as his numerous costly and largely unsuccessful wars, particularly with King Francis I of France, Holy Roman Emperor Charles V, King James V of Scotland and the Scottish regency under the Earl of Arran and Mary of Guise. At home, he oversaw the legal union of England and Wales with the Laws in Wales Acts 1535 and 1542, and he was the first English monarch to rule as King of Ireland following the Crown of Ireland Act 1542.

Henry's contemporaries considered him to be an attractive, educated, and accomplished king. He has been described as "one of the most charismatic rulers to sit on the English throne" and his reign has been described as the "most important" in English history. He was an author and composer. As he aged, he became severely overweight and his health suffered. He is frequently characterised in his later life as a lustful, egotistical, paranoid and tyrannical monarch. He was succeeded by his son Edward VI.

This list of kings and queens of the Kingdom of England begins with Alfred the Great, who initially ruled Wessex, one of the seven Anglo-Saxon kingdoms which later made up modern England. Alfred styled himself King of the Anglo-Saxons from about 886, and while he was not the first king to claim to rule all of the English, his rule represents the start of the first unbroken line of kings to rule the whole of England, the House of Wessex.Arguments are made for a few different kings thought to control enough Anglo-Saxon kingdoms to be deemed the first king of England. For example, Offa of Mercia and Egbert of Wessex are sometimes described as kings of England by popular writers, but it is no longer the majority view of historians that their wide dominions are part of a process leading to a unified England. Historian Simon Keynes states, for example, that "Offa was driven by a lust for power, not a vision of English unity; and what he left was a reputation, not a legacy." This refers to a period in the late 8th century when Offa achieved a dominance over many of the kingdoms of southern England, but this did not survive his death in 796. Likewise, in 829 Egbert of Wessex conquered Mercia, but he soon lost control of it.

It was not until the late 9th century that one kingdom, Wessex, had become the dominant Anglo-Saxon kingdom. Its king, Alfred the Great, was overlord of western Mercia and used the title King of the Angles and Saxons, but he never ruled eastern and northern England, which was then known as the Danelaw, having earlier been conquered by the Danes from southern Scandinavia. His son Edward the Elder conquered the eastern Danelaw, but Edward's son Æthelstan became the first king to rule the whole of England when he conquered Northumbria in 927, and he is regarded by some modern historians as the first true king of England. The title "King of the English" or Rex Anglorum in Latin, was first used to describe Æthelstan in one of his charters in 928.

The Principality of Wales was incorporated into the Kingdom of England under the Statute of Rhuddlan in 1284, and in 1301 King Edward I invested his eldest son, the future King Edward II, as Prince of Wales. Since that time, the eldest sons of all English monarchs, except for King Edward III, have borne this title.

After the death of Queen Elizabeth I without issue in 1603, King James VI of Scotland inherited the English crown as James I of England, joining the crowns of England and Scotland in personal union. By royal proclamation, James styled himself "King of Great Britain", but no such kingdom was actually created until 1707, when England and Scotland united during the reign of Queen Anne to form the new Kingdom of Great Britain, with a single British parliament sitting at Westminster. This marked the end of the Kingdom of England as a sovereign state.