The Godwin family was expelled from England in 1051 by the King, Edward the Confessor. A year later the King was forced to accept the family back when they sailed up the Thames to London with a large force of men. In 1053, Harold's father died and as the eldest son, Harold inherited the title of Earl of Wessex. The king, Edward the Confessor concentrated on the affairs of the church which left Harold to run the affairs of the country, which included fighting the Welsh. Harold had two wives, both called Edith. His second wife was the widow of the Welsh Prince who Harold had defeated in 1063.
Question of succession
Edward the Confessor had no children and an heir to the English throne needed to be found. When it was discovered that Edward the Exile who was the son of Edmund II (Ironside) was still alive, the problem of succession to the throne seemed to be solved and Edward the Exile was invited back to England. Shortly after Edward arrived in England he mysteriously died. Harold may have had something to do with the death as without a nominated heir to the throne, Harold himself could win approval of the English people to be elected King. Edward the Exile brought his family with him to England, including his eldest son, Edgar the Aetheling. After Edward the Exile's death, his family were cared for by Edward the Confessor who nominated Edgar the Aetheling as heir the English throne.
Tostig was Harold's younger brother and Earl of Northumbria. In 1065 he escaped to Flanders after a rebellion against him led by Morcar forced him out of England.
Mysterious events in Normandy
A mysterious meeting is reported to have taken place in Normandy between William the Conqueror and Harold in either 1064 or 1065. In the meeting it was claimed that Harold agreed that William should become King of England when Edward the Confessor died. From what is known of Harold it seems unlikely that he would agree to something like this. Even if the agreement was made, we know that he went against it when assumed the role as King after Edward's death. The Bayeaux Tapestry shows Harold travelling to, or being shipwreked on the land of Guy, count of Ponthieu. Harold was captured by Guy and held at his castle at Beaurain until William the Conqueror arranged for his release. The tapestry possibly shows Harold swearing an oath while his hands rest on what appear to be sacred relics. After this his returns to England.
As King of England
Edward the Confessor died in early January of 1066. Edgar the Aetheling was too young to rule and Harold was crowned King at Westminster Abbey on January 6th.
Tostig was the first to take advantage of King's death and in May invaded England. Tostig was unsuccessful and he had to escape to Scotland where he found refuge. He then travelled to Norway to the court of the Harold Hardrada where he persuaded the Viking leader to assist him with his invasion plans. in September 1066, Tostig and Harold attacked Yorkshire with a huge army of men. At Fulford Gate on September 20th the invaders were met by an English army led by earls Morcar and Edwin and a battle commenced. The invaders won this battle, but on September 25th after marching from the south coast, an English army led by Harold II defeated the invaders in Yorkshire at Stamford Bridge. Tostig and Harold Hardrada were killed in the battle. Shortly after the victory, news that William the Conqueror had landed on the south coast of England meant Harold had to march his army back down the country to fight off another invasion force. On a hill near Hastings, the two armies met. Harold's men fought hard and could have won but after the long marches north and south it may have been to much to ask. William's army was victorious and Harold was killed in the battle. Probably not by an arrow in the eye as hinted at in the Bayeux Tapestry. By December 1066, William, now know as the Conqueror had the support of enough English earls and churchmen to become King of England.