Location(s): Westfold, Grimslade, Pelennor Fields
Title(s): Lesser marshal of the West-mark
Dates: ? to III March 15 3019
Grimbold was a commander under Théodred in the first Battle of the Fords of Isen. He was in command of the rearguard, and then of the garrison on the west bank of the Isen. When Théodred's group was assailed by the axe-men, Grimbold fought his way to his commander's side and slew the orc who had struck Théodred down. Only the arrival of Elfhelm kept Grimbold from death as well.
Erkenbrand assumed command of the group, and gave command of the forces in the field to Grimbold while he gathered more men and made sure of the defenses of the Hornburg. Grimbold, like Erkenbrand, was of the Westfold, and unwilling to abandon the Fords to the enemy; he positioned his men in the earthen forts at the west end of the Fords for the second Battle of the Fords. Althoug his company fought bravely, they were outnumbered and outflanked, and Grimbold withdrew across the Isen.
Eventually he withdrew all his men and formed a shield wall. Desperate as no aid came from Elfhelm, he had some men create a diversion to allow most to escape to join Erkenbrand. Grimbold stayed behind on foot with the rearguard. Saruman's forces did not press their advantage, and Grimbold escaped. Gandalf met Grimbold in the course of his journey the night of the Battle of Helm's Deep, and Grimbold and his men went to join Erkenbrand on Gandalf's advice.
Unfinished Tales, Part 3, Ch V, The Battles Of The Fords Of Isen
At Pelennor Fields, Théoden gave Grimbold command of the left flank, in effect the position of Third Marshal. He commanded the Muster of the West-mark. Grimbold fell in the Battle of the Pelennor Fields.
RotK, Book V, Ch 3, The Muster of Rohan