Battles of the Fords of Isen

The Battles of the Fords of Isen were two battles between the forces of Rohan and Isengard that took place at the Fords of Isen during the War of the Ring.
=== First Battle of the Fords of Isen ===
Saruman's main obstacles in conquering Rohan swiftly were Théoden's son Théodred and his cousin Éomer, for these two men were strong-willed and skilled warriors. Saruman knew he had to kill them as soon as possible in order to achieve victory, so he launched an attack on the Fords of Isen, which was a very important strategic position in Rohan, for it was the only way for large armies to cross the Isen River. Prince Théodred personally commanded the Riders to victory, but after the battle it was very obvious to the Rohirrim that Saruman had clearly given orders to his troops to kill the crown prince of Rohan at all costs. If Saruman had sent his troops into battle with the aim to destroy the Rohirrim, this would have surely been a victory for Isengard and not Rohan. He would have been able to continue the conquest of the Westfold and destroyed the army sent out from Edoras before it reached Helm's Deep to reinforce the tiny garrison there. Even Gandalf's arrival at Edoras could have not happened, and the war would have been won by Isengard.
Théodred had heard of a troop-gathering in Isengard, and wanted to defeat Saruman's army before it was fully gathered. He left three companies of cavalry on the eastern shore whilst he himself took eight companies and a company of bowmen to meet Saruman's troops. But Saruman had already gathered all his troops and sent them south, where they dug in and waited for Théodred and his army. Theodred defeated a troop of Orcs
about 20 miles north of the Fords and went on to attack the main army, not knowing that they were expecting him. He ran into them, and wanted to retreat, but fresh troops from Isengard had fallen on his western flank. The companies following Théodred's arrived soon and defeated the enemies in Théodred's rear. But as he looked across the river, he saw another army of Isengard marching south to the Fords, for Saruman had built a bridge allowing him to send armies down both sides of the Isen.
Théodred immediately ordered a retreat to the Fords, but they were followed by the Orcs. Grimbold took command over the troops on the western shore, and Théodred took the little hill in the middle of the river to guard the passage in case Grimbold had to retreat. But Isengard’s eastern army had now engaged the Rohirrim on the eastern shore and attacked with Wargs, followed by two battalions of Orcs. The unprepared Rohirrim on the eastern shore were swiftly destroyed, and Théodred's retreating army, who were on the eastern shore, fled south along the Isen, being chased by the Orcs all the while. As the Orcs had control over the eastern shore, they sent a troop of orcs armed with axes to attack the little hill Théodred was holding. At the same time, Grimbold was attacked on the western shore. The Dunlendings had surrounded the hill and were closing in on Théodred and his men, who cried for help. Grimbold heard this and took a small company of Rohirrim around him to aid Théodred. He hewed a path through the axe-men and reached Théodred a second too late, as he was struck down by a big orc. Grimbold killed the orc and thought Théodred was dead; and if it were not for Elfhelm, he himself would have died that very moment.
Elfhelm had come from Edoras and led four companies of cavalry into the battle to reinforce the beleaguered Rohirrim. Isengard's forces were surprised by this new army coming from the east as the Sun rose over the horizon. In the blinding sunlight, the Orcs thought that Elfhelm brought a far larger army than he actually did, and many fled from the field—the deserters were pursued by two companies of Rohirrim, while those that stood their ground were all killed. Elfhelm had ordered the other two companies to guard the eastern shore and took his own guard to charge the hill where Grimbold was fighting. The Dunlendings were being attacked from both sides and were soon killed. The Rohirrim still held both shores, and Elfhelm charged up the hill to where Grimbold was fighting for Théodred's wounded body. Elfhelm rescued Grimbold, and they bent over Théodred to hear his last words: "Let me lie here to protect the Fords, until Eomer arrives". He died soon after speaking those words. As night fell, the Orcs at the western shore retreated. The next morning Théodred’s troops that were chased south by the initial Orc force returned.
=== Second Battle of the Fords of Isen ===
The command of the ford's garrison was given to Erkenbrand of the Westfold. However, until he arrived from Helm's Deep, Grimbold held the position. Grimbold decided to place foot soldiers at the ford and put Elfhelm's men on the east side where he expected the attack to come from.
Saruman sent a force which was small, but which still outnumbered the defenders. The attackers forced Grimbold to retreat across the ford with heavy losses. Grimbold held the eastern side of the ford and waited for Elfhelm to come to his aid. More than half of Saruman's force was attacking Grimbold's position.
Some Warg Riders and their followers went through the gap between the two Rohirrim forces and tried to surround Elfhelm. Although he knew Grimbold was in danger, Elfhelm retreated eastwards. Grimbold was still holding his position when he saw torches coming from the north and from Isengard - the vanguard of Saruman's reinforcements advancing towards him. Before he knew it, they had crossed the ford. He could not hold the ford so he retreated to his camp and made a shield wall around it.
Even though the Rohirrim were surrounded, still the forces of Isengard could not break through. Grimbold knew he could not hold out forever. With no sign of Elfhelm and no help from Erkenbrand, he decided to try to break out. He mounted all the riders for whom he had horses and made a gap on the east side of the shield wall through which the riders passed. They formed into two groups and attacked the north and south sides simultaneously. In the ensuing confusion, the remaining Rohirrim retreated on foot as quickly as they could in the dark.
Saruman's commander had broken open Rohan's border and now moved on to his next objective - the Hornburg.