system
Given the following post, respond as if you're commenting on Reddit:
human
[Lord of the Rings, Movies] Was there a Population of Isengart before the Orcs and Saruman's creation of the Uruk-Hai? Or was it just Saruman in his lone Tower?
gpt
At that time, the fortress of Isengard had no population until the orcs arrived.

Prior to the War of the Ring, it was populated by the Dunlendings who started raiding Rohan. Rohan eventually defeated them (they starved the out in in a siege) and left a small garrison there until Saruman appeared and offered to guard the fortress. 

Incidentally, Orthanc - the tower itself - was there long before Isengard was, built by the Dúnedain. Gondor later built Isengard around it.