Both William and Harald began mustering armies in preparation for an invasion of England. Harold of England acutely aware of the danger to his new position, spent the summer of 1066 on the south coast with a large army awaiting the Norman armies invasion. However with the onset of Autumn the English king infamously allowed his fyrd to return home for the upcoming harvests; a move that may have ultimately led to his later defeat.

Throughout this initial scramble for the throne Harold’s brother Earl Tostig, likely a dreadful man, exiled due to his own unpopularity, left for Flanders to acquire a fleet to challenge his brothers rule. Initially he made a landing on the Isle of Wight but was forced to retreat when Harold called out land and naval forces to oppose the landings. Earl Tostig sailed northwards to East-Anglia and Lincolnshire conducting raids across the area. However he was beaten back by the brothers Edwin Earl of Mercia, and Morcar Earl of Northumbria. 

Without ships or men Tostig fled first to Scotland then to Norway, where according to one Saga he convinced a very uninterested Harald Hardrada to invade England. Though we may never know the truth, this is certainly an interesting theory!  

Despite not being a likely contender for the throne, Tostig's actions may have deeply influenced the outcome of 1066. Had he not sailed to Norway perhaps the Saxon army would have been free to face William unhindered? 

Hardrada's invasion fleet was ready to sail in September. According to the source, King Harald's saga, the Norwegian sailed with around 200 ships. He first stopped in the Viking occupied Orkney and Shetland islands to resupply before picking up 2000 troops from the Scottish King Malcolm III. This combined force may have numbered between 9000 and 11,000. Upon arriving in England they sailed up the river Ouse towards York, meeting the brothers, Edwain and Morcar at the battle of Fulford just outside the city. The Norse army would have fought in a similar fashion to the Saxon army, largely on foot with mostly close combat infantry, Shield-wall clashing with shield-wall. The wealthier soldiers could afford mail coats however it is likely that many fought without armour and simply a shield. The most terrifying weapon at their disposal was the famous Dane axe, a two handed weapon that could take off a horses head or split a shield in one blow.

Edwin and Morcar's Saxon army numbering around 5000 was severely outnumbered. They had to spread their lines thin to secure the armies flanks. This meant the army was wedged between the river Ouse and a Swampy area called the Fordland, meaning if one flank crumbled the other would be unable to retreat due to the difficult terrain. The army itself was predominantly composed of infantry, a mix of fyrd militia and professional Housecarls; the typical arrangement of a Saxon army.

Harald's much larger army approached from three routes to the south. Its size meant progress was slow and segments of the army would take hours to trickle in. Knowing this the English Earls decided it would be best to attack early before the Viking army could completely muster. The Saxons advanced securing good early progress against the weaker flank of the Norwegian army, however this momentum could not be sustained. With the arrival of fresh Viking troops the situation became dire for the English. 

Harald struck at the centre of the English line with fresh troops, eventually succeeding in splitting the army; at this moment it became a slaughter. The Saxon army was utterly crushed with a few survivors making it back to York. The Earls Edwin and Morcar both managed to escape and the city of York would surrender shortly after to the victorious Viking army.

Hearing of the Viking landing near York, Harold forced marched his army northwards at breakneck speed, covering a distance of over 185 miles in four days. (There is debate as to whether he mounted his best infantry so they could cover the great distance in as short a time as possible) Completely unaware of this danger the Viking army split leaving a third with their boats and the rest travelled to Stamford bridge, leaving behind their armour due to the late summer heat. The sudden appearance of the new Saxon army spread fear throughout the unprepared Viking ranks, however Hardrada being a grizzled veteran of many wars encouraged his men and prepared them for battle.  

According to Viking chronicler Snorri Sturluson, prior to the battle a lone Saxon rode up to Harald Hardrada and Tostig offering the return of Tostig’s earldom if he would turn against Hardrada. When asked what Harald would receive in this deal?the rider replied "Seven feet of English ground as he is taller than other men”. Impressed by the individual’s boldness Hardrada asked who this man was? to which Tostig revealed it was Harold King of England.

A single bridge delayed the Saxon advance allowing Hardrada to form his men in a defensive position. A single Viking blocked the bridge wielding his Dane axe challenging any Saxon to cross. The story goes that he slew 40 English before finally being stabbed from under the bridge by a Saxon warrior who decided subterfuge was the best option.

Harold’s army then poured across the bridge and harassed the Viking shield wall using skirmishing archers, slingers and javelin men whilst the English prepared their battlelines. Eventually both sides clashed and battle raged for hours but the Vikings started to crumble due to having left their armour at the ships. According to chroniclers the Norwegian King was in the thickest fighting and slew many Saxons, however as his shield wall began to disintegrate Harald Hardrada was struck through the windpipe by an arrow. With the death of their King and Tostig the Viking army was routed and with not many returning to Scandinavia to tell the tale. Harold had successfully secured the North; however a greater threat would emerge in the South. 

William had assembled a vast army with troops from across the entirety of France and he had particularly large contingents of Breton and Flemish soldiers. The Duke's army mustered at Saint-Valery-sur-Somme and with his banner blessed by the Pope giving him divine right by the 12th of August was ready to cross the Channel. Contemporary sources have vastly inflated the size of Williams army, some suggesting he had as many as 150,000 men. In reality the exact numbers and composition of William's army are unknown, a logical estimate seems to be between 10,000 and 12,000 men. This force would have been composed of cavalry, infantry and archers/crossbowmen and camp followers.

Although the army and fleet was ready by early August, unfavourable winds kept the Norman army at bay until late September. Some historians have also suggested that intelligence reports revealing Harold's army deployed on the southern coast may have influenced the decision to delay the landing as William preferred an unopposed landing.

William landed on the 28th of September at Pevensey and built wooden fortifications at Hastings. From this base the Norman army raided the local area, hoping to entice the Saxons into attacking. The plan worked. Harold rushed south leaving parts of his army in the north. Had he delayed, the Saxon army would have been in better shape and greater numbers for the battle to come. 

The speed at which Harold decided to mobilise was an attempt to catch the Normans by surprise. A plan that failed due to William's scouts successfully spotting the army. Sources generally agree that William decided to gather his forces and march out to meet the Saxon army, hoping a decisive victory could be achieved. Harold had taken up a defensive position upon Senlac hill and waited for William's army.

There is no reliable data for the size or composition of the Saxon army. It is generally accepted that the likely number would be between 6000 and 8000 men. The army would have been a mix of fyrd, a militia mainly containing foot soldiers, and the housecarls, the professional soldiers and hearth-guard of noblemen. The fyrd would usually wear little armour, a shield and perhaps a helmet if lucky, whilst housecarls would have a mail coat, helmet, shield and either spear or the dreaded Dane Axe. The English army had some archers and slingers but mainly spear armed infantry and Housecarls and formed a dense defensive shield-wall on the high-ground.

The battle began at 9 am on the 14th of October and lasted the entire day, an extraordinary length of time for a battle to last. The Normans began by sending archers to unleash volleys of arrows on the Saxon shield wall, these had little effect against the tightly overlapping Saxon shields. William then sent forward his infantry. The Norman army had been divided into three contingents, Bretons on the left flank, Normans in the centre and a mix of French and Flemish troops on the right. After a bloody first attack, the Norman army had failed to make breaches in the shield wall, support from the cavalry was also fruitless; this led the Breton left flank to begin a route that spread across the army, chaos ensued. A rumour spread that William had been killed in combat spreading further panic and a pursuit by the Saxon troops placed the entire army in jeopardy. It was at this moment that William rode forward with his face exposed, rallying his men and leading a counter-attack against pursuing English. This proved decisive, the pursuers were surrounded and butchered and the Norman army regained its composure. 

There is debate as to whether the Breton flight was actually a deliberate withdrawal or feigned flight as this was a traditional hit and run tactic used by the javelin armed Breton cavalry. Deliberate tactic or not! William continued to use feigned flight tactics throughout the day, weakening the Saxon line little by little, drawing out rash Saxons in pursuit. It is assumed that Harold specifically ordered his men to hold their positions as breaches in the shield wall would be catastrophic, these orders were foolishly ignored.

Throughout the day the battle remained a stalemate with high casualties on both sides. The decisive moment of the battle came late in the day with the death of the English King. The cause of Harold's death is a source of much speculation. The Bayeux tapestry has two potential depictions of the death of Harold; one showing a Saxon with an arrow in his eye and a second showing a Saxon being cut down by horsemen. It is also possible that both depictions are accurate and that he was cut apart after being hit by an arrow. William is said to have sent a death squad to take out Harold on the battlefield. When he was killed they cut off his genitals and head, before  hacking him to pieces. Allegedly Harold's lover, Edith Swanneck, is said to have only been able to recognise his corpse by secret marks on his body only known to her.

With the death of Harold the Saxon army was leaderless and began to disintegrate, only the soldiers of the royal household gathered around Harold's body and fought to the end. The final stand of the Saxons marked the end of the battle, William had emerged victorious and would go on to complete his conquest of England.

Over the following years, the Saxon nobility would go on to be almost entirely replaced. Much of the Saxon nobility would flee England  and go on to join the Varangian guard in the court of Constantinople. Those Saxons that stayed and attempted to challenge William would face dire consequences, the harrying of the North would be the most brutal example of William's ruthlessness, a systematic devastation of Northern England. Life in England would remain fundamentally changed.

The Anglo-Saxons had occupied England from the late 400s following Roman withdrawal from the island. Over this period a distinct English culture emerged that still has influence on the isles today. Originally England was divided into four main Kingdoms, Northumbria, Mercia, East Anglia and Wessex. These Kingdoms were unified by Athelstan in 927 AD, creating one of the wealthiest and most powerful Kingdoms in Northern Europe. This period of prosperity lasted until 1016 AD when Cnut took the English throne and established the North Sea Empire. From this moment instability plagued the politics of Anglo-Saxon England. Eventually the ruling class of the nation would be replaced following the Norman conquest of England.

The Normans could trace their origins to Rollo, Count of Rouen, a Viking who, in 911 AD was granted the territory of modern day Normandy, in exchange for a pledge of allegiance to the king of France. The Norman people were therefore a product of the intermingling of Norse settlers and Frankish locals, they were essentially French Vikings. These people had a major political, cultural and military impact on medieval Europe; going on to establish colonies across the continent, from the Holy lands, to Sicily, to England. The Normans left their cultural mark across the medieval world, they were fearsome conquerors and ruthless rulers and perhaps had the most significant  influence on Northern Europe since the Romans.

Viking was a name given to the collective seafaring people of Scandinavia. From the 8th century these people raided and traded across Europe. This period is known as the Viking age and only ended in 1066 with the defeat of Harald Hardrada at Stamford bridge drawing a close to the great Viking invasions of England. Minor raids continued well into the late 11^th and early 12^th Century. These people were feared and traded with across Europe. Originally Pagan they began to Christianise around the 900’s. Often their raids turned into full scale invasions. In 1016 AD Cnut the Great succeeded in uniting the Kingdoms of Denmark, Norway and England, creating the North Sea Empire and creating as new Anglo Danish-aristocracy. This would have a direct influence on the later Norman invasion.