The Ktilacs were a species that trace their origins back to the planet of Ktil, located in the Inner Rim. These beings held dominion over sixty-three star systems within the Ktilac Regions, a spatial territory shared with the Murachaun and Tocoyans. These three groups shared a unified culture and a similar religious belief system. Ktilacs' home planet was at one point part of both the Galactic Republic and the Galactic Empire. Despite their tendency towards isolationism, the Ktilac Regions maintained the status of an Allied Region under both the New Republic and the Galactic Federation of Free Alliances.
The sentient Ktilacs were a species whose homeworld was the planet of Ktil, situated in the Inner Rim within the collection of star systems known as the Ktilac Regions. The Ktilacs, alongside the Tocoyan species from the desert planet Tocoya and the reptilian Murachaun from the grassy world Nahsu Minor, cultivated a shared culture and a quasi-religious system. This system emphasized the complementary nature of each of the three species within the Ktilac Regions. Their belief system considered the rest of the galaxy to be unholy. Consequently, Ktilacs found outside the Ktilac Regions were considered exiled apostates. Around 25 ABY, the Ktil population was estimated to be between ten and one hundred million individuals.
Each of the Ktilacs, Murachaun, and Tocoyans held sway over sixty-three star systems within the Ktilac Regions, an area generally closed off to outsiders. The exploration of the space surrounding Ktil occurred between 20,000 BBY and 15,000 BBY. By 17,000 BBY, the Ktilacs' home planet had been integrated into the Galactic Republic, positioned along hyperlanes controlled by Alsakan and its allies of the Core Worlds during their political struggle against Coruscant, the galactic capital. Ktil was located within territories either unaligned with or contested by the Republic and the Brotherhood of Darkness during the concluding years of the New Sith Wars, by which time the Republic's territory had diminished significantly.
By the time the initial campaigns of the Clone Wars unfolded in 22 BBY, Ktil had once more become a member of the Republic. However, by 17 BBY, the Ktilac homeworld had been absorbed into the territory controlled by the Galactic Empire. Twenty-nine years later, the planet was part of the New Republic, with the Ktilac Regions retaining their status as an Allied Region under both the New Republic and its successor, the Galactic Federation of Free Alliances. During their invasion of the galaxy, the extra-galactic Yuuzhan Vong attacked and conquered the Ktil system at some point between 26 ABY and 27 ABY, but it was no longer under their control in 27 ABY.
The name of the Ktilacs initially appeared in Alliance Intelligence Reports, a 1995 sourcebook for Star Wars: The Roleplaying Game by West End Games, within a mention of the Ktilac Regions. It wasn't until the 2009 reference book The Essential Atlas that the Ktilacs were first described as a distinct species.