In April 1066, six months before the battle of Hastings, Halley’s Comet was seen in the sky across Europe. But comets were considered to be bad omens at the time so William used it as proof of Harold’s improper succession.

There were three kings of England during the tumultuous year of 1066, beginning with Edward the Confessor. He had ruled for over 20 years before dying in the first week of the year. Without a son or heir, his death left a struggle for the throne between several competing would-be kings, including William of Normandy; Harald Hardrada, king of Norway; and Harold Godwinson – who quickly arranged a coronation for himself on 6 January.

From his rushed coronation on 6 January, Harold II was king of England for 282 days before he was killed at the battle of Hastings. He had no dynastic claim to the throne but he was a powerful magnate in the kingdom and asserted that Edward the Confessor had named him as successor on his deathbed.

Hastings is the best-known battle in the Norman Conquest, but it was just one of three major actions fought in England in 1066. The battles of Fulford (20 September) and Stamford Bridge (25 September) repelled a Viking invasion led by Harald Hardrada shortly before William the Conqueror won the battle of Hastings on 14 October. William was then crowned on Christmas Day of that year.Read more: Hastings, Stamford Bridge and Gate Fulford: three battles that lost England

William was a relative of Edward’s, but his chief claim was that in 1051, Edward had allegedly promised him the throne. He backed this up by stating that Harold Godwinson had, two years before Edward’s death, sworn to support William’s succession. When Harold took the crown, William began planning an invasion to take back what was promised to him.

With Harold II’s forces up north fighting Harald Hardrada, William and his fleet of nearly 700 ships landed without incident on 28 September 1066. The journey had only been 60 miles, from Saint-Valery-sur-Somme in France to Pevensey. From there, William made his way inland, attacking villages on the way.

Harald Hardrada was unaware that King Harold II was marching north with all haste to meet him. So when the two armies met at Stamford Bridge, a third of Harald’s army were back at camp. What’s more, it was a hot day so the Vikings had left their armour and even weapons behind. Despite Harold’s forces being outnumbered, the Anglo-Saxons defeated them and Harald Hardrada himself was killed. The Viking fleet had consisted of hundreds of ships when it first sailed, but only 24 were needed to carry the survivors of the battle away.

Harold’s Anglo-Saxon forces had the better defensive position at the start of the battle. Placed at the top of Senlac Hill, William’s archers and cavalry couldn’t be used to full effect and as the day dragged on, William wasn’t getting anywhere. The Normans began to retreat but when Harold’s forces followed them, they turned on the pursuing Anglo-Saxons.

There has been a lot of debate over how Harold died, but the most lasting story is that he was shot in the eye with an arrow. On the Bayeux Tapestry, there is a figure who was thought to be clutching an arrow sticking out of his eye under the statement, "Here King Harold has been killed". But there is a second figure who could also be Harold. He is falling to the floor after being cut down by a man on horseback.

The Bayeux Tapestry is almost 70 metres long, and it used to be even longer as the end is now missing. It's suggested that Odo of Bayeux, one of William’s half-brothers, probably commissioned it to be hung in a new cathedral on the Normandy coast. It is one of Britain’s greatest surviving historical sources, but it technically isn’t a tapestry – it’s an embroidered cloth.