The Lord of the Rings has a lore that's potentially the most in-depth in fiction in the past two centuries. As a result, there are ages of history to uncover as well as the origins of some of the most terrifying and benevolent beings in the canon. This meant that by the time modern audiences were introduced to the works of J.R.R. Tolkien, there were more than enough stories to sift through, and the events surrounding The One Ring were a small blink in a larger history of Middle-Earth.
One of the most interesting species within the lore was the Orcs. By the Third Age, Orcs were monstrous creatures with a severe aversion to sunlight. They served under Sauron and Saruman and were said to be the product of Elves who succumbed to dark magic and torture. Their very presence and numbers only complimented their naturally ravenous behaviors and compensated for their frail form. Even still, the most elite of them, the Uruks, carried a power that made them more formidable.
The Uruk-Hai's History in The Lord of the Rings, Explained
It's said that Uruks were a creation of Sauron and a more elite version of the Orcs. They were stronger, faster and much larger than an average Orc and were more inclined to fit the warrior category. Furthermore, they were more violent than any of the Orcs that came before. However, during the time of Saruman, he saw a chance to improve on this subspecies even further, leading to the creation of the Uruk-hai.
Uruk-Hai were bred by Saruman in Isengard and were speculated to be the crossbreeding of Orcs and Men. That said, while he was shown to have a more hands-on approach with the Uruk-hai, he merely added to what was already created by Sauron. To do this, Saruman utilized dark magic to fill in the necessary gaps and give the Uruk-hai life. In doing so, he also cured them of a crucial weakness, enhanced them to even higher levels and used them for many battles.
How Saruman Improved His Uruk-Hai With Magic
Being a cross of Elves and Men, this iteration of Uruk-Hai had an advantage over the Orcs that would make a difference in battle. The main difference twas that these creatures no longer had an aversion to sunlight. While they were unhappy at the prospect of walking out during the day, they could withstand it much more than the average Orc. As a result, this allowed for surprise attacks, like when Lurtz led his army to attack the Fellowship in broad daylight.
Saruman effectively used his magical skills to turn a subspecies of Orcs into violent super soldiers. While that's a more crude term to describe Tolkien's more regal fantasy world, it's clear there are parallels between Uruk's and the many enhanced characters that came in other mediums. However, what made this iteration of creatures so terrifying was how crude science and dark magic turned them into something unstoppable. Ultimately, it would take the combined might of Gimli, Legolas and Aragorn to defeat a whole battalion, and by the end, they were almost completely drained. Uruk-hai may be the most dangerous creatures in all of The Lord of the Rings, and it all came from the desire to cure them of their weakness to sunlight.