The Lower City represented a district within the sprawling urban landscape of the planet Taris, existing approximately 4,000 years prior to the Battle of Yavin. This area primarily housed the less affluent segments of Tarisian society. Notably, nonhuman inhabitants were largely restricted to this sector due to pervasive discriminatory practices and legal constraints rooted in anti-alien prejudice. Positionally, the Lower City resided beneath the towering structures of both the Middle City and the Upper City, while simultaneously being situated above the depths of the Undercity. The uppermost levels of the Lower City were characterized by impoverished neighborhoods, with streets marred by widespread squalor and discarded waste.
Several centuries prior to Taris's emergence as a significant hub, the Taris Civil Authority orchestrated the construction of the Lower City atop the Undercity. Subsequently, the Middle City was built above the Lower City, followed by the Upper City above the Middle City. Consequently, the Lower City was deprived of direct sunlight and unobstructed sky views due to the imposing presence of the massive skyscrapers.
When Rakghouls mysteriously appeared within the planet's Undercity, they frequently utilized elevators originating from the sewers to ascend into the Lower City and launch assaults on its residents. However, the local populace consistently emerged victorious in these confrontations against the spread of disease.
In 4056 BBY, the non-Human population of Taris was compelled to reside within the Lower City following the conclusion of the Tarisian Civil War. Concurrently, the Outcasts were banished to the Undercity as a consequence of the victory of Tarisian Human nobles and some alien nobles. Subsequently, taxes were increased to benefit the government's interests within and above the Lower City. Eventually, the lower levels became ungoverned by law, which was a primary reason for the locals' boycott of the government. Numerous gangs then began to oppress the ordinary citizens of the Lower City.
Control of the Lower City's streets was a point of contention marked by rivalry between various swoop gangs. The intergalactic criminal syndicate known as The Exchange perpetuated an atmosphere of fear within the Lower City since 4000 BBY, with the exception of the Black Vulkars during the swoop gang war. The most prominent swoop gangs were the Hidden Beks, led by Gadon Thek, and the Black Vulkars, led by Gadon's adopted son Brejik, from 3976 BBY to 3956 BBY.
Later, Juhani and her family were compelled to reside in one of the Lower City's most impoverished slums after fleeing the Mandalorian assault on her home planet, Cathar. Her species, or at least her subspecies, was considered alien even among the non-humans of Taris. From Juhani's perspective, it represented the worst aspects of the galaxy.
During the Mandalorian Wars, the Lower City was subjected to attacks by the Mandalorians. Many Exchange members, including the slaver Xor and the slave Juhani, sold their slaves to the Mandalorian Neo-Crusaders. The Jedi Order, led by Revan, liberated the slaves. The Republic, led by Saul Karath succeeded in dissolving the Taris Civil Authority and driving the Exchange off the planet. The Jedi Order managed to free the slaves but the Mandalorian presence did not lift. The Taris Resistance held them off until they were defeated and retreated to the Undercity so they could escape aboard The Last Resort, which was based there. With the Exchange's withdrawal along with the Galactic Republic and the Jedi the Mandalorians governed the Lower City along with the rest of Taris. With the Mandalorians' withdrawal or possibly exiled by Revan and Malak in the aftermath of the war, the Exchange occupied the Lower City once more, with little to no difference.
During Revan's involuntary stay on Taris, he and Carth discovered that Bastila was being held captive as a prize in the swoop racing competition. After gaining access to the Undercity, using the elevator to enter the Black Vulkar Base and massacring almost everyone inside, Revan and his party were able to recover a prototype accelerator, to install on a Swoop Bike. Then racing and winning for the Beks, freeing Bastila and killing Brejik, before fleeing to the Upper City Apartments and were recalled by Canderous Ordo to Javyar's Cantina. Revan could also have either lifted or collected bounties from the Hutt Zax. Following the destruction of Taris by Darth Malak, the Lower City potentially had a relatively significant number of survivors compared to the Upper City, where most inhabitants perished. However, according to the Outcasts, there were none.
By 3 ABY, the Lower City had undergone reconstruction by Human colonists, albeit without the segregation that existed in 3956 BBY, as the Tarisian nobles and anti-alien Humans had died during the orbital bombardment. As for 40 ABY, Boba Fett journeyed to the Lower City in pursuit of stolen cloning information to cure himself of a severe ailment.