In May, King William began his expedition from London, and this new army included 2,000 Englishmen, mainly from Devon and Cornwall, with a total strength of 10,000 men, including 2,000 cavalry, 6,000 infantry, and 2,000 crossbowmen. The king first followed the road north to Warwick and captured the important town of Mercia almost without blood, and he ordered Henry, son of Roger, of Beaumont, to build a castle there, leaving forty knights to defend it. The Normans then advanced in the direction of Leicester, and by the time they reached Nottingham, there was still no resistance, only some roads and streams were damaged and blocked, causing some trouble for Norman supplies, and King William built a castle in Nottingham as usual, leaving William Peverer and fifty knights in charge of the garrison, the young Norman nobleman was rumored to be the illegitimate son of King William and was favored by the court.

At this time, news came from eastern Lincolnshire, that Hereward, with the support of the governor of Lincolnshire, had established a large camp on the island of Erie, that the Normans had been completely expelled from the marshes, and that some of the knights who had been given the territory had been killed by the English, and in this way, a veteran soldier of Thorn had turned the whole of East Anglia upside down.

The King of England, who was herding horses in Nottingham, decided to march east to Lincoln at once to cut off the connection between these resisters and the rebels in the north, and he selected 900 knights, led most of the infantry and began to march eastward, and the remaining main force was on the spot to protect the flank of the Crusade army against the invasion of the Welsh in the west and the Mercian in the north.

Almost at the same time as the Normans turned eastward, the sons of Harold in Dublin, led by Godwin, invaded the southwest with 50 ships, and they soon plundered the vicinity of Somerset, where the English led by Roger of Montgomery and the Breton knights of the Earl of Bryan were in Bristol on the River Avon to assist the Earl of Hereford against the Welshmen of Gwynness and Edric the "barbarian". The ships from Dublin plundered from Somerset westward at Devon and Cornwall, but they were unable to secure the support of the local English, and all the fortified towns were closed, and Exeter was heavily fortified, and Harold's three sons saw that they had no chance to take advantage of it, so they returned with the plunder.

After the news of the Normans' march north, the Mercians were still besieged in York, but after hearing that Warwick had fallen, both earls decided to submit to the king again, although they did not want to go south, after all, the last time they were brought to Normandy made both counts extremely wary. The two men were determined to continue the blockade of York, and then surrender after the king had gone north, in order to obtain a promise to retain the territory. In order to achieve this, the two counts did not want the Normans to become too powerful in the north, so the king had to rely on himself to keep the situation stable. So the Earl of Morka secretly sent two hundred Northumbrians of Hugh Barn to Lincoln to support Marl-Sween and Hereward. Under the strong pressure of the king's army, the governor of Lincolnshire immediately led all his troops south into the marsh area, and destroyed the roads and dikes, and the king who had nothing to gain in Lincoln could only build a castle on the spot and go south to the marsh area, the English from Peterborough, Raven Land, Bilmine and other regions used the island of Erie as a stronghold to constantly harass the Norman army on the march, Herry Ward's militia and the Northumbrians of Hughed used the dense forests and moors to attack day and night, and the Normans divided the army into many detachments, And the villages along the way were fortified on the spot, King William ordered all churches and monasteries to supply the royal army, which further provoked the rebellion in the marsh area, some priests and monks not only sheltered the fleeing English, but even took the initiative to lead the Sein and Kerles to join the resistance, the Normans were unbearable, and some of the English in the Norman army began to circulate all kinds of legends, people mentioned Prince Alfred, who was killed by Earl Godwin in this swamp thirty years ago, this noble royal family, King Edward the Confessor's younger brother was rowed by Godwin's soldiers to the island of Erie, where he was blinded and eventually died a tragic death on the island under the care of some priests. Some Englishmen swore they had seen Prince Alfred's ghost in the woods and swamps, while others said the area had been cursed by the water-hag.

After nearly two months of fighting and plundering, King William hated and could not do anything about the mosquitoes in the swamp of Hereward's men. Ignorant of the geography and unable to conquer the rebel-entrenched island of Erie, the king lost faith in the short-term suppression of the rebels in Hereward, leaving behind some troops to fortify northern Lincolnshire and blockade the rebels, leading his exhausted main force out of the woodland.

At the beginning of June, news from Lincolnshire boosted the morale of the English people in the north, and the two earls in York even temporarily dismissed the idea of surrender, and began to try to persuade the Normans defending the city to surrender, but William Mallett still did not let up, and the Mercians had no interest in attacking the fortified city, so they could only continue the siege.

When the king returned to Nottingham, feeling that his prestige had been taken as a sign of weakness and that the enemy on all sides would be ready to move, the king, who had only taken a short rest, immediately mobilized nine hundred knights and put them under the command of Robert of Comina, and ordered him to set out at once to rescue York.

The Norman knights meandered in columns along the eastern avenue of the Peaks, the hills to the west were undulating, sometimes infested with foraging foxes, and the roads were lined with scattered villages and fields, while the Normans, who did not want to reveal their whereabouts, were only concerned with the journey, and did not stop except to feed the horses with grain. Count Robert constantly encouraged all the knights to keep up with their spears and not fall behind.

Two days later, the Normans had crossed the Eyre River in Tansherford, and some English soldiers were stationed on the banks of the river, and when they saw the Norman cavalry on the other side of the bridge, they immediately began to shout loudly, and Robert de Comina immediately ordered Robert Fitzrichard to go out with ten knights to the bridge and take up the guard. The English soldiers' camp was on the dry high ground on the bank of the river, and the bridge was not blocked, but their camp was surrounded by sharpened wooden fences, and Robert Fitzrichard ignored the enemy, but let the knights dismount and defend the bridge, and set up a flag gun, so the whole Norman cavalry began to cross the bridge in small columns. The whole process flowed like a stream into a stream, and the English soldiers had already been successfully crossed by the Normans before they could even respond, and the militiamen from Mercia listened to the sound of horses' hooves like a raging tide, and all of them turned so pale that they did not even send messengers to the north. The English sentries in the camp watched the iron-clad enemy cavalry shine brightly in the sun, and never heard a word of order from the Earl of Mercia, who commanded it.