For thousands of years Coruscant has been considered the most politically significant planet in the galaxy. As a result of its prime location at the intersection of several hyperspace lanes, Coruscant has been universally regarded as militarily and economically invaluable by individuals and governments seeking to dominate galactic politics. As a focal point of galactic power, the planet has also taken on immeasurable social significance, to the point that it is often regarded as the center of the galaxy despite being many light years away from the true center. Throughout history, those who have sought control of Coruscant have developed it so heavily that the planet has effectively become, in essence, a single giant city. Its location made it the envy of most governments and the target of more than one invasion. This has led to Coruscant having a unique history, one so long that its origins are unknown to most, including its own residents.
Originally Coruscant was a lush, green planet inhabited by the Taung, a humanoid simian race of warriors, and the Battalions of Zhell, a group of thirteen human nations sometimes considered the ancestors of humankind. After centuries of warfare the Zhell suffered near extinction when a volcano destroyed their homelands and blackened the skies of Coruscant with ash. The Zhell would eventually recover and drive the Taung from their homeworld, becoming the first Coruscanti. The displaced Taung would go on to colonize Roon and eventually Mandalore, becoming the Mandalorians.
Since that time the Coruscanti have taken advantage of their strategic position in the galaxy, amassing fantastic wealth and power, albeit at the expense of their planet. Due to the heavy industrialization and the paving over of all natural terrain on the planet, the atmosphere is heavily taxed and requires constant atmospheric scrubbing, lest it become toxic to all life.
Militaries have all but destroyed Coruscant during numerous wars, leaving many of the once majestic structures in rubble. However, with each war comes a new wave of rebirth across the city-planet, with new structures built directly upon the wreckage of the old. It's often theorized one could catalog the history of galactic warfare based solely on the construction techniques and materials present at each layer of the city. This theory has not been proven, as most historians refuse to venture into the bowels of the planet for fear of the lower socio-economic classes that reside there.
While the kilometers of buildings rising from the planet have been rebuilt time and again, one thing that hasn't changed is the systems underneath. Beneath the bustle of upper Coruscant, and the less than lawful activity within the lower regions, there lies the planets "core." While not many who reside on Coruscant know what or where it is, everyone knows it exists. Built long ago by the Gree, a less than social race whose reasons for constructing the under-works are still unknown, it has run efficiently despite the many conflicts that have plagued the planet.
In recent history, Coruscant is most notable as having been the seat of power for the Galactic Republic until the emergence of the Galactic Empire which was created in its wake. As the Capital of the Empire, Coruscant has continued to flourish. Development has continued both on the planet and in the star system, and numerous defensive emplacements have been constructed, including a halo of orbital defense platforms around the planet and the surrounding space. The Galactic Empire often places their top military academy graduates on these platforms to further develop their skills. They are then groomed to eventually captain the Empire's fearsome Star Destroyers.
Although Coruscant may be the center of the galaxy, as well as a cultural and economic hub, the planet's long history still remains a mystery; one which many seek to solve.