Uruk-hai in the Black Speech means Orc People. They were also called Uruks and Great Orcs.

The Uruk-hai were thought by some to be the result of a blasphemous blending of the races of Orcs and Men on the part of Saruman the White. Others claimed that the Uruk-hai had been bred by Sauron.

The Uruks were larger than other Orcs, and looked rather man-like. They were unaffected by sunlight and were excellent trackers, because of their sense of smell. They were a strain of Orc that could travel great distances. They were stronger, faster and more intelligent than the normal Orc.

Sauron used them as soldiers, and they were first seen shortly before Osgiliath was taken by the dark forces in 2475 of the Third Age. They fought with swords that had straight blades.

They were used in the War of the Ring by Saruman to hunt for the Ringbearer. However, Saruman's band of Uruk-hai, led by Uglúk, took the wrong two hobbits hostage, and then he and his band were killed by the Rohirrim while the hostages (Merry and Pippin) got away.

Many Uruk-hai perished at the Battle of the Hornburg.