Ambush at Fangorn Forest

This ambush was conducted by a company of Rohirrim led by Éomer against a mixed force of Uruk-hai from Isengard and Orcs from Mordor and the Misty Mountains. It occurred in late February of 3019 T.A., near the edge of Fangorn Forest.

Description

The Uruks, who had been carrying two prisoners (Meriadoc Brandybuck and Peregrin Took) in tow, were anxiously attempting to reach Isengard as quickly as possible. However, they were joined by an Orc of Mordor named Grishnakh, as well as a company of Orcs from the Mountains. Grishnakh was seeking the One Ring to deliver to his master Sauron's Ringwraiths, and the latter group sought revenge against the Fellowship of the Ring for their previous intrusion in Moria.

This led to a series of disagreements with the Uruks that delayed their progress many times. During one of these conflicts, a few of the Mountain-Orcs were killed, leading to Grishnakh disappearing and returning with a squad of Mordor-Orcs.

By the time the three parties came to an agreement, the riders of Rohan had caught wind of the Orcs and Uruks (due to their failure to kill one of their scouts), and pursued them across Rohan. In a panic, most of the Mountain-Orcs fled ahead, but were debilitated by the bright sunlight and left for dead by the Isengarders as they reached the eaves of Fangorn Forest.

There, the Rohirrim launched their final attack and wiped out all of the Orcs and Uruk-hai present. Éomer himself engaged in a duel with Uglúk, the leader of the Isengarders, and slew him.

Aftermath

During the confusion, Merry and Pippin managed to escape their captors and avoid most of the conflict by disappearing into Fangorn Forest, where they would later meet Treebeard. The Rohirrim piled the corpses of the slain Uruks and Orcs on the battlefield and had them burned.

Portrayal in adaptations

2002: The Lord of the Rings: The Two Towers:

The circumstances of the battle are simplified or outright changed; The force of Orcs consists of Uruk-hai led by Uglúk and Orcs seemingly loyal to Grishnakh.

When the Orcs start quarreling over whether or not they would eat one of the Hobbits, Uglúk decapitates one of the Mordor-Orcs, and his Uruks began cannibalizing its corpse.

At this point, Grishnakh catches Merry and Pippin attempting to escape, only to be shot by an arrow. It is at this point where the Rohirrim launch their attack from out of the darkness. However, unlike the book, Grishnakh survives the battle and pursues Merry and Pippin into the forest, where he is killed by Treebeard.

2002: The Lord of the Rings: The Two Towers (video game)

Although omitted from the console versions, the GBA version features another, more drastically-altered version of the ambush. The battle appeared to have occurred between the Uruks of Isengard and a group of Orcs from Mordor. The former seem to have been victorious, and drove the latter into the forest, where they are presumably killed by Huorns.