So who were these five men who all believed they should be England’s king?
1. Harold Godwinson
The brother of Edward’s wife, Harold was the leading noble in England and the man who Edward supposedly gave the kingdom to on his deathbed. Harold was crowned king on 6 January 1066 but would only last a few months in the job. In September of that year he successfully fought off an attack by one rival claimant to the throne, Harald Hardrada. But less than three weeks later he was killed in battle with another claimant: William the Conqueror.2. William of Normandy
William, Duke of Normandy, believed that Edward had promised him the English throne long before Harold. Edward, who was William’s friend and distant cousin, supposedly wrote to the French duke to tell him England would be his in as far back as 1051.Incensed by Harold’s coronation, William gathered up a fleet of around 700 ships and, with the backing of the pope, set sail for England — once the winds were favourable. After arriving at the Sussex coast in September 1066, William and his men had their confrontation with Harold on 14 October. After winning what became known as the Battle of Hastings, William was crowned king on Christmas Day.
3. Edgar Atheling
Edgar, Edward the Confessor’s great-nephew, may have been the king’s closest blood relative at the time of his death but he was never a real competitor in the battle to succeed him. Just a teenager when Edward died, Edgar had also spent the early years of his life in exile in Hungary and was not considered politically strong enough to hold the country together.He did, however, join forces with the king of Denmark in 1069 to launch an attack on William. But that attack ultimately failed.
4. Harald Hardrada
This Norwegian king’s claim to the English throne stemmed from an agreement supposedly made between his predecessor and a former king of England: Hardicanute. Hardicanute had only ruled England briefly between 1040 and 1042 but that did not stop Harald from believing that the English crown should be his. After teaming up with none other than King Harold’s brother, Harald took an invasion fleet of 300 ships to England.The Viking warrior had some initial success, defeating English forces at Fulford, on the outskirts of York, on 20 September 1066, before seizing York itself four days later. Both Harald and his invasion met their end the following day, however, when King Harold and his men defeated the Vikings at the Battle of Stamford Bridge.
5. Svein Estridsson
Svein, King of Denmark, was Harold Godwinson’s cousin but believed that he may too have a claim on the English throne because of his own connections to Hardicanute, who was his uncle. It was not until William was king, however, that he seriously turned his attentions to England.In 1069 he and Edgar sent a force to the north of England to attack William but, after capturing York, Svein reached a deal with the English king to abandon Edgar.
Source: https://www.historyhit.com/the-claimants-to-the-english-throne-in-1066/