Grimbold was a Rohan commander from Grimslade. He led the Riders of Rohan during the First Battle of the Fords of Isen along with Elfhelm and Théodred and killed many Orcs. Soon he had to retreat due to the death of Théodred. He distinguished himself during the Second Battle of the Fords of Isen by holding off a large army of Orcs for an extended period of time, then staging a retreat with minimal losses when enemy reinforcements arrived. He was killed during the Battle of the Pelennor Fields outside of Minas Tirith.
He can be recruited at level 5 at the King's Camp and then equipped with one of various battalions. He is very similar to Elfhelm, Erkenbrand and the Rohan Captain. The battalion will not disband if the upgraded Marshal is killed, unlike the Thrall Master, but you will be unable to use the ability until they regenerate.
Grimbold can be given one of the following upgrades:
Soldiers of Meduseld - Call a battalion of Soldiers of Meduseld to serve as elite Swordsmen. Cost: 500
Wardens of Meduseld - Call a battalion of Wardens of Medused to serve as elite Pikemen. Cost: 600
Knights of Meduseld - Call a battalion of Knights of Meduseld to serve as elite Cavalry. Cost: 800
StrategyThe strategy you use with him depends on the situation, what faction you are up against, etc. This is due to his special use of 3 different upgrades which give him 3 different kinds of elite units. The Knights could be used for spammy factions or factions with many archers, the Soldiers to counter enemy pikemen, or the Wardens for cavalry- based factions like Rohan. Also, once he dies and you revive him he is able to re-choose the battalion he will lead. He makes nearby battalions fearless, and his active ability can make troops go faster and have more armor, which is useful to get in combat and make an impact.