The Uruk-Hai were bred by the Dark Lord Sauron and Saruman the White replicated the process building his own army of Uruk-hai. The Uruk-hai thus made up a large portion of the armies of both sides of evil.
The Uruk-Hai are faster than normal Orcs and could travel during the day without being weakened by the sun. They are not only faster but stronger and larger: unlike Orcs, they are taller than Men. They are believed to be a crossbreeding of Orcs, Goblins and Men.
Saruman the White's army of Uruk-hai fought against King Théoden of Rohan and his people at Helm's Deep. Saruman's Uruk-hai had an "S" elf-rune wrought in white metal on the front of their iron helms. It was clear this "S" stood for Saruman, because their shields had a small white hand (the symbol of Saruman) centered on a black field.
The Orcs and Uruks in the service of the Dark Lord Sauron of Mordor, used the symbol of the red Eye of Sauron. The Red Eye was also painted on their shields. At least one, a guard, on the march with Merry and Pippin had a black knife with a long saw-edged blade, used by Pippin to cut through the ropes on his hands. These Uruks of Mordor referred to Sauron as the Great Eye, and Grishnákh was their Captain. They could see better in the dark, were braver and more deadly than Saruman's Uruk-hai
Beware the Uruk-hai of Saruman the White and even more so the Uruks of the Dark Lord of Mordor.
