Antiquity and early Middle-Ages
43 AD:  beginning of the conquest of Britain by the Romans except for Scotland which remained separated by Hadrian's Wall. They founded London, brought Christianity and maintained control of their province of Britannia until the 5th century.
5th century: beginning of the Anglo-Saxon invasion, which is often considered to be the origin of England and the English people. They were a collection of various Germanic peoples ( Jutes, Saxons and Angles). They established several kingdoms (Northumbria, Mercia, Kent, East Anglia, Essex, Sussex, Wessex, ...). This is also the period of the legendary King Arthur. 
9th century: frequent raids by the Vikings who took control of a region in the west and the centre of the island, called the Danelaw. They even ruled the country, alternately with the Anglo-Saxon House of Wessex, under a dynasty of Danish kings, the most famous being King Canute (1016-35).

Middle Ages: House of Plantagenet
12th century: Henry II of England, the great-grandson of William the Conqueror, founded the House of Plantagenet which ruled England for most of the Middle-Ages (from 1154 until 1485). He married Eleanor of Aquitaine and was succeeded by their son Richard I "the Lion Heart". Richard  was succeeded by his younger brother John Lackland. Apart from entering popular legend as the enemy of Robin Hood, King John is perhaps best-known for facing an armed rebellion of the barons of English nobility, which forced him to accept in 1215 the Magna Carta (the Great Charter). This imposed legal limits on the king's personal powers: “No Freeman shall be taken or imprisoned […] but by lawful judgment of his Peers, or by the Law of the land”. 
In 1348 , the Black Death, an epidemic of bubonic plague that spread over the whole of Europe, arrived in England and killed as much as a third to half of the population.
From 1337 to 1453, the Hundred Years' War was a series of separate wars between the Kings of England and the French House of Valois who both claimed the French throne. The war was a defeat for the Kings of England after the appearance of Joan of Arc (1412–1431).

16th century: House of Tudor
The junior branches of the House of Plantagenet, the House of Lancaster and  the House of York, clashed in a civil war known as the Wars of the Roses which ended in 1485 with the victory of Henry Tudor, who became Henry VII and founded the House of Tudor.
Henry VIII (1509-47) succeeded his father. He started a conflict with Rome when he wanted to divorce his first wife Catherine of Aragon to marry Anne Boleyn.  This ultimately led to the separation of the Church of England from the Roman Catholic Church with the English monarch as the Supreme Head of the Church of England. Henry VIII is also famous for his six wives, two of whom were beheaded (among which Anne Boleyn). He was succeeded by his only son Edward (1547-53), then Catherine of Aragon's daughter, Mary I (1553-58), nicknamed "Bloody Mary" because of the massacres of Protestants during her reign, and finally by Elizabeth I (1558-1603) the daughter of Anne Boleyn. She was sometimes called the Virgin Queen, as she never married. Her reign began with the defeat of the Spanish armada in 1588, seen as one of the greatest victories in English history.  Elizabeth's reign is known as the Elizabethan era, famous for the Protestant Reformation, and above all for the flourishing of English drama, led by playwrights such as William Shakespeare.

17th century: House of Stuart
In 1603, The King of Scots, James VI, of the House of Stuart, the closest male relative of Elisabeth I, became King James I of England in a Union of the Crowns of England and Scotland. Several assassination attempts were made on him, notably, in 1605, the Gunpowder Plot, by a group of Catholic conspirators, led by Guy Fawkes, which caused more antipathy in England towards the Catholic faith.
In 1642, the English Civil War broke out, as a result of conflicts between James' son, Charles I, and Parliament. The defeat of the Royalist army by the Army of Parliament led to the capture and trial of Charles resulting in his beheading (décapitation) in 1649 in London and making England a republican Commonwealth. Oliver Cromwell, a commander of the Army of the Parliament was given the title Lord Protector in 1653, until his death in 1658. The monarchy was restored in 1660, with King Charles I's son, King Charles II, returning to London. 
In 1679, the Habeas Corpus Act was passed by the Parliament of England to define and strengthen the ancient prerogative writ of habeas corpus, whereby persons unlawfully detained cannot be ordered to be prosecuted before a court of law. After the death of Charles II in 1685, his Catholic brother King James II was crowned. Due to widespread objections to a Catholic serving as the King of England, there were various factions pressing for the Dutch Protestant Prince William of Orange and his wife, Mary, King James's daughter, to replace the latter in what became known as the Glorious Revolution. 
In 1688, William landed in England with an invading force, was crowned king and finally defeated James at the Battle of the Boyne in 1690. 

18th century: a growing Empire
In 1701, Britain took part in the War of the Spanish Succession against Spain and France which saw the defeat of the latter in 1714. At the concluding peace Treaty of Utrecht, the British Empire was territorially enlarged: from France, Britain gained Newfoundland and Acadia, and from Spain, Gibraltar.
In 1707, the Acts of Union between the Kingdom of England and the Kingdom of Scotland were passed by both parliaments, and dissolved them in order to form a Kingdom of Great Britain governed by a unified Parliament of Great Britain according to the Treaty of Union. 
In 1714, The House of Hanover succeeded the House of Stuart as monarchs of Great Britain and Ireland and held that office until the death of Victoria in 1901.
In the 1740s and 1750s, during the Carnatic Wars in India, the British East India Company struggled with the French as the Mughal Empire declined in power, and the British finally defeated the French and their Indian allies, leaving the Company in control of Bengal and a major military and political power in India.
In 1763, the signing of the Treaty of Paris putting an end to the Seven Years' War was the result of a major British victory over France. In North America, France ceded its territories in Canada to Britain. Spain ceded Florida to Britain. It therefore left Britain as the world's dominant colonial power.
In 1775, the American War of Independence began. In 1776, the colonists declared the independence of the United States and with economical and naval assistance from France, they won the war in 1783, depriving Britain of its most populous colony.
In 1770, James Cook discovered the eastern coast of Australia during a scientific voyage to the South Pacific. In 1778, Joseph Banks, Cook's botanist on the voyage, presented evidence to the government on the suitability of Botany Bay for the establishment of a penal settlement, and in 1788 the first convicts arrived in Australia.

19th century
In 1801, the Act of Union created a new state called the United Kingdom of Great Britain and Ireland, which united the Kingdom of Great Britain with the Kingdom of Ireland to form a single political entity. The English capital of London was adopted as the capital of the Union.
In 1803, war was declared against France as a consequence of the advent of Napoleon in France and Europe who threatened to invade Britain. In 1805, the Royal Navy won a decisive victory over the French fleet, under the command of Admiral Nelson, at Trafalgar. The Napoleonic Wars were however a period of great sufferance in Britain largely because of the naval blockade imposed by the Emperor on the island. They ended following Napoleon's final defeat against a coalition led by the Duke of Wellington at Waterloo in 1815. 
In 1837, Queen Victoria began a 63-year-long reign which would see Britain reach the zenith of its economic and political power. Exciting new technologies such as steam ships, railroads, photography, and telegraphs appeared, making the world much faster-paced.
In 1846-49, 'The Irish Potato Famine' as known in Britain and in Ireland as 'The Great Hunger' left much of the Irish rural population without food. About one million Irish people died and another million emigrated, mostly to America.
In 1899-1902,  the Boer War took place in South Africa between Britain and the Dutch settlers (Boers) there, with a final victory for Britain.