Henry I, also known as Henry Beauclerc, was born in England in 1068. He was the youngest son of William the Conqueror, and the first to be born in England after the Normans invaded. With Henry being the youngest, he was never expected to inherit much, especially not the throne of England.
Despite this, he was crowned king of England in 1100 and subsequently Duke of Normandy in 1106. Henry is well known for the political and judicial changes he made during his reign, such as reforming the treasury and granting a Charter of Liberties, subjecting him to the law, all in a time before Magna Carta was ever written.
However, later in his reign tragedy struck and he lost his one legitimate heir to the throne. This caused a major succession crisis, and civil war soon broke out.

Early Life
Henry was the youngest of four sons, and in line with family tradition, he was expected to become a bishop. He was afforded a great education for the time; the name ‘Beauclerc’ was given due to his great scholarly interests, and he may have been the first Norman king to speak English fluently.
Henry had three brothers – Richard, who died in a hunting accident, William Rufus, and Robert ‘Curthose’. When William the Conqueror died in 1087, his three surviving sons inherited different things. William Rufus was to claim the English crown and become William II, Robert to take the Duchy of Normandy and become Duke Robert III, and Henry to receive only 5,000 pounds of silver – not a great deal in comparison to his brothers.
Henry attempted to pit his brothers against each other, but they were wary of his schemes and signed a treaty that stipulated that Henry be barred from the throne of both kingdoms and could only claim them under the circumstances of William or Robert dying without an heir, something they were, of course, not planning on doing.
Sibling Rivalry
When William II was crowned king, he took any lands that Henry was entitled to and demanded a share of his silver. Henry blatantly refused, so William instead offered him land in Normandy for a share of the silver. Henry accepted the offer and became a count in western Normandy.
Henry is said to have managed his lands well and without the interference of his brothers. With this success, he wanted to reclaim his lands in England and so crossed the English Channel to confront William, but his requests were refused.
Back in Normandy, rumours were circulating that William was making an alliance with Henry and planning on taking Duke Robert’s inheritance. Upon Henry’s return, he was imprisoned by Robert and his title in Normandy was removed. He was eventually released due to his noble status. However, William was still not content, and he convinced Conan Pilatus of Rouen to turn against Robert. A small battle broke out and Robert fled, but Henry bravely stayed to fight and captured Pilatus.
For his part in the conspiracy, Henry took his prisoner to Rouen Castle and threw him from the roof. This was unusually cruel for a man of Henry’s stature, but it sent a strong message to anyone who wanted to rebel against him. William and Robert were also clearly shocked by Henry’s actions and were soon back on better terms. They signed the Treaty of Rouen, which claimed they would support only each other and exclude Henry completely.
This caused some more friction between the brothers and Henry failed to get his revenge, he was unable to amass an army large enough to take on his siblings. Over the years, tensions died down and Robert eventually left to join the First Crusade. William took advantage and took control over some of Normandy, while also during this time he and Henry slowly reconciled.

Crown and Marriage
With Robert away on Crusade and William and Henry back on brotherly terms, it would seem that events would soon take a steadier course. However, on one fateful day in August 1100 William and Henry went out on a hunt, and William was accidentally shot with an arrow. This proved to be fatal.
With Robert being absent, Henry stole his chance and immediately rode to Winchester, where he occupied the castle there. He buried his dead brother and sustained enough support from the leading barons, claiming that he would bring England into a new era of peace and security. He was crowned King of England three days later at Winchester Abbey.
In November of the same year Henry married Edith, daughter of King Malcolm III of Scotland. Edith had the roots of the old Saxon bloodline, being the niece of Edgar Atheling and the great-granddaughter of Edmund Ironside, who was the half-brother of Edward the Confessor. This in turn joined the Norman line with that of the old Saxon Kings of England.
However, some of the Norman nobility were unhappy with the marriage; she changed her name to Matilda when she became queen, pleasing the Norman barons and putting any animosities to rest. It proved to be a good match, and Matilda was known to be a good queen, fulfilling her regal duties as well as providing an heir to the throne.
Henry had a son named William, who became known as ‘Atheling’, which is an old Saxon term for ‘prince of royal blood’. While this was Henry’s legitimate heir, he is said to have had many mistresses, possibly fathering over twenty illegitimate children who, while he supported them faithfully, were always aware of their illegitimacy to the English crown.

Conquest and the Battle of Tinchebray
Henry was determined to take Normandy and reclaim it as an English realm under the possession of the crown. In 1101, Robert crossed to England with an army in an attempt to invade. The two brothers met at Alton to negotiate, and the Treaty of Alton was formed. Henry was recognised as king by Robert, and in return he was allowed to return to Normandy in peace, with Henry also providing 2000 marks annually.
Unfortunately, the peace did not last. In 1104, Henry accused Robert of allying with his enemies and Normandy slowly began to falter, with many of the barons and noblemen siding with Henry. In 1105, Henry took an army to Normandy and invaded. Negotiations were tried once more, but this time they failed, and the fighting continued.
On the 28th September 1106, the brother’s armies met unexpectedly at a crossroads in Tinchebray. The brutal onslaught didn’t last long, and Henry gained the upper hand. Duke Robert attempted to retreat but was captured, and Henry had won the day.
England and Normandy
Henry proceeded to imprison Robert, he was first held at the Tower of London, but then moved to Devizes Castle, and eventually Cardiff Castle. He spent the rest of his days imprisoned and died in captivity, while Henry had achieved his goal of reuniting England and Normandy, the duchy now once again in possession of the King of England.
Robert’s son, William Clito, attempted to regain his father’s lands, but Henry always managed to keep them under his control. Clito died in 1128 after a battle wound became infected, his father outlived him by six years.
In 1120, Henry, his son William Atheling, and many others were due to make a return trip to England from Normandy. A vessel called the White Ship had been prepared for the king, but he had made other arrangements. Instead, his son, two of his illegitimate children, and many other nobles boarded the White Ship.
The crew had apparently asked William Atheling to drink with them, and he supplied plenty of wine for everyone. As night came, the captain ordered the ship to sail, wanting to show off the newly refitted vessel by reaching England before the king. However, with a drunk crew and not much light, the ship struck a rock and capsized.
William Atheling was swiftly moved to a lifeboat by his personal guard, but as people struggled in the freezing water they attempted to climb aboard, causing it to also capsize. There is only one known survivor of the White Ship, a butcher from the town of Rouen; everyone else aboard died. William Atheling’s body was never recovered, and this drunken accident would later lead to chaos.

Henry’s death and the future of England
The death of Willing Atheling was a tragedy, and the king was inconsolable, a wreck of grief; he now had no male heirs to continue his legacy. Henry’s first wife had died in 1118, so he married again, this time to Adeliza, daughter of Godfrey the I of Leuven. This proved to be fruitless, as they had no children together. Henry convinced his barons to accept the daughter from his first marriage, Matilda, as his heir.
Henry died in December 1135 from food poisoning. He was in Normandy at the time, his remains were taken back to England and buried at Reading Abbey, a place he had founded himself only fourteen years earlier. The Abbey was destroyed during the Reformation, and his tomb was never found, but a plaque and memorial cross can be found where the place once stood.
Henry’s death caused a revolution called The Anarchy. Even though those loyal to him had sworn allegiance to Matilda, her gender and marital status stopped her from taking the crown – a woman had never ruled over England, and she was married to Geoffrey of Anjou, an enemy of the Normans.
Instead, Henry’s nephew Stephen rushed to Winchester and made his claim. The barons preferred him over Matilda, and he became King of England. Stephen was a great warrior but not a brilliant leader, despite this he won many military endeavours in order to keep a tight grip on his claim. Times became more difficult for him when he arrested the Bishop of Salisbury, where he then lost the support of the church.
Matilda allied with her half-brother Robert of Gloucester in 1138, and by 1139 she attempted an invasion of England. Stephen allowed her safe passage to Bristol, and his barons were shocked at such incompetent leadership. In 1141, Stephen was captured in Lincoln and imprisoned at Bristol, and Matilda took control for a brief period, but her ally and half-brother Robert had also been captured by Stephen’s loyalists. This prompted an exchange of hostages, both were released and Stephen managed to reclaim the throne. Matilda had left England by 1148.
Stephen’s reign caused misery for most of England. His warring with Matilda as well as his lack of leadership caused this, with mercenaries roaming the countryside, raping and pillaging wherever they went, as well as nobles and barons fighting their own disputes. There was no safety or security in the realm, which Stephen ruled until 1154.
Stephen had hoped to pass the throne onto his own son Eustace, but he was dead by 1153. In the same year, Matilda’s son Henry of Anjou had invaded England – he had come back to take his crown. After the death of Eustace and the threat of Henry on his doorstep, Stephen gave up and signed a treaty that claimed Henry would be his heir upon his death.

Stephen died in 1154, and Henry of Anjou took the crown and his grandfather’s lands back. This effectively ended the Norman line of kings; Henry II was a Plantagenet, the first of his kind, and the future of England was far from over.
References
https://www.britannica.com/biography/Henry-I-king-of-England
https://www.historic-uk.com/HistoryUK/HistoryofEngland/King-Henry-I/