The Talocan era
The Anoikis star cluster is situated at a distance of roughly 1500 light years from Amarr, far beyond the reach of modern jump drives. It is believed to have been first colonized over 6000 years ago by an ancient and advanced race, the Talocan. They were masters in manipulating spacetime, far outstripping even the Jove in that particular science. We now believe that the Talocan could alter the very fabric of spacetime to allow easy travel via artificially generated wormholes.
There was a control hub for these artificial wormholes, hidden in our very own cluster, in the system W477-P. This hub would have consisted of a vast orbital lattice surrounding the W477-P star. One of the functions of this stellar swarm was to generate and stabilize wormhole passages at will. There have been rumors of similar hub in Anoikis, but to this date it has not been found.
The Talocan used this technology to maintain a network of interstellar routes in Anoikis, in our cluster (bypassing jump gates), and between them. Some believe that the Talocan even manipulated the locations of the stars in Anoikis or the strength of their gravitational field, but that is generally considered far-fetched.
The Talocan vanished, both from our cluster and from Anoikis. We do not know what happened to them, nor exactly when they vanished. They left behind only a handful of derelict structures, among which the wormhole control hub around W477-P, which has kept functioning until fairly recently.
The Sleeper era
A certain faction of the Jove, the Sleepers, discovered this wormhole travel hub, sometime near the end of the Second Jove Empire, roughly 1000 years ago. The Jove of this faction are called Sleepers because their bodies reside in permanent hibernation, and they live their lives as disembodied infomorphs in virtual space. They did not inform the other Jove about the Talocan highway to Anoikis. The Sleepers relocated, in secret, to Anoikis to escape the internecine Jove wars that ended the second Jove Empire.
It is only fairly recently, three hundred years ago, during the Third Jove Empire, that their brethren found out where they had gone to. By then, Sleepers had thoroughly colonized Anoikis and had become its new inhabitants, heirs to the Talocan. You will encounter Sleeper structures in wormhole space, and their drones are still active there. They will attack you, for example while you mine. They will become more ferocious going from class 1 to class 6 holes.
The Seyllin cataclysm
All this time, the passage to Anoikis remained a well-kept secret - parhaps only known to the Society of Conscious Thought or the Sisters of Eve. This changed abruptly on March 10, YC 111, when a cataclysmic event occurred that revealed Anoikis to all.
That day, the type-O giant blue star at the center of the Seyllin system in the Federation erupted with a ferocity never seen before. The eruption resulted in an highly energetic and strongly-focused plasma flare that not only destroyed the Gallente colony on Seyllin I, but also reached a hidden entryway to the Talocan wormhole network.
The flare's energy was injected in the hidden Talocan network, leading to an overload of the network and a concomitant overload of the Talocan stellar engine at W477-P. The wormhole control hub was critically damaged. As a result, the wormhole connections were no longer kept in check and became uncontrollable. Suddenly, hundreds of unstable wormholes opened up all over New Eden, offering temporary pathways into Anoikis that could be traversed by our ships.
A mere six years after the Seyllin cataclysm, W477-P went supernova, and the Talocan control infrastructure stabilizing the wormhole network was lost. The remnants of the supernova can still be seen in the sky, and are known as Caroline's star. As a result, for the foreseeable future, wormholes will continue to appear randomly throughout our cluster, and they cannot be stabilized any more.
The Capsuleer era
Wormhole connections to Anoikis are short-lived and randomly connect stars. This inherent instability is why the Empire's rule of law cannot be enforced in Anoikis, and no territory can be claimed. At first, Concord tried to ban all travel to Anoikis, but this travel ban was soon defied. The first (non-Jove) person to enter Anoikis was a Jin-Mei astrophysicist from CryoDron, Lianda Burreau. She is believed to have died at the hands of the Sleepers.
Of course, capsuleers and their organisations -attracted by the lawlessness of the place- could not be stopped either. They are now the de-facto (third-wave) colonists of Anoikis, battling over its resources with the remnants of the previous inhabitants, the Sleepers.