Peregrin Took
After lengthy deliberation (three days; though from the perspective of the Ents this was almost no time at all), they march on Saruman's fortress at Isengard - 'the last march of the Ents'. Led by Treebeard, the oldest Ent, and accompanied by the hobbits Meriadoc Brandybuck and Peregrin Took, the Ents numbered about 50, plus an army of Huorns. They destroy Isengard, tearing down the wall around it: "If the Great Sea had risen in wrath and fallen on the hills with storm, it could have worked no greater ruin".) Saruman is trapped in the tower of Orthanc.