
Flag of England featuring Saint George's cross. The legend of Saint George tells about a knight saving a princess from a horrific dragon. The image of Saint George slaying the dragon features on many British coins.
History
English medieval and early modern history is quite complicated, even though its population was relatively small compared to for instance France until the 17th century. England was often the scene of various power struggles that involved both local and continental powers, but eventually became a formidable power itself, especially through its navy and trading companies.
Antiquity
Prehistoric Britain was inhabited by various Celtic tribes. The Romans invaded Britain in 43 AD and ruled over a part of the island that roughly corresponds with modern day England. After the Romans left in the year 410, Germanic Anglo-Saxons invaded the island and pushed the Celtic tribes further west and north to Wales and Scotland.
Anglo-Saxon period (410-1066)
By the 7th centiry several Anglo-Saxon kingdoms existed, such as Northumbria, Mercia, Wessex and East Anglia. In 865 the Danes invaded and conquered large parts of Britain, but it was Wessex that resisted the most and eventually drove the Danes out and unified the territory in 927 under King Æthelstan. In the early 11th century the Kingdom of England was shortly united with Denmark and Norway.

Anglo-Saxon kingdoms on the British Isles in the year 802.
Norman Conquest and the House of Normandy (1066-1135)
When the last Anglo-Saxon king Edward the Confessor died in 1066, a power struggle erupted between Edward's son-in-law Harold Godwinson and King of Norway Harald Haldrada. At the same time Duke of Normandy William also claimed the throne and invaded England that same year. He won the Battle of Hastings which earned him the title of William the Conqueror.

William the Conqueror on a (pre-Sterling) Penny. The design was heavily influenced by contemporary Byzantine coinage.
William struggled to get a grip as the first King of England from the House of Normandy. He replaced most Anglo-Saxon noblemen with Norman ones which had a dramatic effect on the English language, which quickly became a mix of Anglo-Saxon Germanic and French. Even though the Normans had originally come from Norway a century earlier, they had already adopted a version of the French language.
House of Plantagenet (1154-1485)
The House of Normandy came to an end when Henry I died in 1135. He was succeeded by King Stephen of Blois of the House of Boulogne, who struggled for power with Henry's daughter Matilda. Together with her second husband Geoffrey Plantagenet, count of Anjou, Matilda fought King Stephen in a civil war known as The Anarchy (1135-1153). Geoffrey and Matilda's son Henry was eventually victorious in 1153 and was crowned King of England a year later, the first of a dynasty that would rule England for 331 years.

The first Penny of the Pound Sterling, featuring King Henry II. Minted between 1158 and 1163.
Their rule produced the first constitution in the world, the Magna Carta, first published in 1215. It was however not a sign of enlightenment, but rather sheer necessity to appease the continuously rebellious English noblemen. Due to their Angevin (from Anjou) roots the Plantagenets had many possessions in France, where a succession crisis led to the Hundred Years' War (1337-1453). And after this war, which saw England lose all its continental possessions, two branches of the Plantagenets fought each other in the Wars of the Roses (1455-1487).
House of Tudor (1485-1603)
The first Tudor King, Henry VII, defeated the last Plantagenet Richard III at the Battle of Bosworth Field in 1485. His son, Henry VIII, who reigned from 1509 until his death in 1547, is best known for his six marriages and his 'Brexit avant la lettre' by separating the Church of England from the Roman Catholic one after he wanted to divorce his first wife because she did not give him a male heir. It marked the start of a long religious struggle between catholics and protestants.

Henry VIII on a Groat (4 Pence)
Henry VIII was succeeded by three of his children. At first his son from his third marriage, the protestant Edward VII, held the throne, but he died at a young age. Subsequently Henry's daughther from his first marriage, Mary, a devout catholic, took power. Her harsh treatment of protestant opponents earned her the nickname Bloody Mary, a name currently better known as an anti-hangover cocktail. Mary died childless in 1558, and was succeeded by her protestant stepsister Elizabeth I.

Elizabeth I on a Sixpence
The reign of Queen Elizabeth I (1558-1603) is widely considered to be very successful. Her youth was quite troublesome. At the age of 2, her father Hendry VIII had her mother, his second wife, executed on the accusation of adultery. Her stepsister Queen Mary in turn imprisoned her for conspiring with protestant English noblemen. Despite this Elizabeth was a broadly skilled monarch, who had to manage a religious conflict at home and a war with Spain (1585-1604). The war established England as a naval power and the first expeditions to the New World were made at that time. Elizabeth I never married and died childless in 1603.
House of Stuart (1603-1714)
Elizabeth I was succeeded by King James of the House of Stuart, King of Scotland and a distant cousin of Elizabeth. James brought England and Scotland into a personal union but they officially remained two separate kingdoms.
Religious strifes continued to dominate English politics. The catholics often revolted to regain the throne, and the protestants criticised the kings for not being harsh enough. A civil war (1642-1651) broke out and a puritan movement eventually took power in 1649 and sentenced King Charles I to death. Until 1660 England was de facto a republic, although some refer to it as a interregnum. The Cromwell brothers were the most prominent political leaders of that time.

A Shilling from the Commonwealth of England (1649-1660), the only period in English history so far that it was not ruled by a monarch.
In 1660 Charles II resumed the Stuart monarchy. He was a popular king, who had numerous children with his many mistresses but his wife sadly had only stillborn children. His catholic brother James II succeeded him in 1685 but was quickly deposed by a protestant movement in the Glorious Revolution of 1688. Mary, James' daughter, and her husband the Dutch Stadtholder William III became King and Queen.
Under William & Mary England became a constitutional monarchy with the Bill Of Rights signed in 1689. They had no children and were succeeded by Mary's sister Anne in 1702. It was Anne who unified England and Scotland in 1707 to establish the Kingdom of Great Britain. She was the last to hold the English throne and the last monarch of the House of Stuart as she died without issue in 1714. Queen Anne was succeeded by her distant cousin George I of the House of Hanover, who ruled as King of Great Britain.
Currency
Anglo-Saxon coins
From 620 to 675, gold coins were minted worth 1/3 of a Roman Solidus. They were named Tremissus in Latin or Thrymsa in Anglo-Saxon. After 675 only silver coins named Sceat were minted in England and in Frisia (now Netherlands). Some but not all of these silver coins can be attributed to specific Anglo-Saxon Kingdoms of the time.
Early versions of the Pound
The British Pound has its origin from the Carolingian monetary system that was set in Europe in the 8th century. It set a silver standard whereby a Denarius or Penny was equal to 1/240 of a pound, a unit of weight at that time equal to around 350 grams. It was introduced to England by King Offa of Mercia (757-796).
Pound Sterling
Frequent debasements led to the introduction of a new coinage in 1158, which is seen as the birth of Pound Sterling. The weight was now based on the Tower Pound, equal to almost 454 grams of silver. The name sterling has 2 potential origins. It either refers to Norman pennies that featured a star, or it refers to Hanseatic merchants bringing silver pennies of .925 pureness to English ports, where they were called Easterlings (coming from the east). This .925 would remain the name for sterling silver and the basis of British currency until the adoption of the gold standard in 1816.
The £sd non-decimal system
The Pound's subdivision was in 20 Shillings, each of 12 Pence. A Penny was divided in 4 Farthings. The name Shilling was derived from Latin Solidus, which was a Roman coin, and the name Farthing is derived from Fourling, as there were four in a penny. This system would remain until 1971, when the UK decimalised its currency into 100 New Pence. But over the centuries other denominations did emerge and others disappeared.
The silver Groat
The need for more denominations led to the introduction of the Groat of 4 Pence in the late 13th century. It was originally based on the Venetian Grosso which was known in France as Gros, and as such was brought to England where it became known as the Groat. From the 18th century the minting of Groats became irregular. But in the West Indies it was a popular denomination as it was roughly equal to a Spanish Real. In the 19th century some British Fourpence were therefore minted for colonial use. Over time, also half Groats of 2 Pence were minted.
The gold Noble
England's first gold coin was the Noble intriduced in 1344. It had a weight of around 9 grams and was valued at 1/3 of a Pound, although later values and weights would fluctuate.
Debasement during the Middle Ages
The silver standard of 20 Shillings in a Pound of sterling silver did not last. In 1354 it was devalued 20% so that 25 Shillings of currency were needed to weigh one pound. In 1412 this became 30 Shillings, so in other words a Pound Sterling was now equal to 303 grams of sterling silver. In 1552 a new coinage was introduced that reflected 60 Shillings in a Pound, and 1601 this became 62 Shillings.
The gold Guinea of 21 Shillings
In 1663 the first gold Guinea was struck with a weight of 8.4 grams of .917 gold. It was initially valued at 20 Shillings, but fluctuated up to 25 Shillings that same century. It was fixed to 21 Shillings in 1717. The Guinea earned its name as the gold used to mint the first coins originated from Africa. The name is still used today in parts of the Arab World as a local name for the Pound.
The Crown of 5 Shillings
The Crown was a coin of 5 Shillings introduced in the early 16th century as a gold coin. Later large silver versions were minted as well and gold was phased out over time. The large silver coins were popular with collectors but were seen as rather unpractical for daily use. The term 'crown-sized coin' still exists today for large coins of around 38mm in diameter.
https://en.numista.com/catalogue/england-1.html