They just don't know how to leave us alone do they
— unnamed human regarding Earth's constant changing of hands
Earth, or Helios III as it was known on galactic charts, was a planet in the Unknown Regions that was one of the several human homeworlds littering the galaxy. Due to its system's position in the galaxy, it was often an area of conflict in the various wars since the Clone Wars.
Before the Clone Wars, Earth was a bustling planet with no contact with the rest of the galaxy. It was barely space faring and could easily be consitered primitive compared to the rest of the galaxy. However, the planet was discovered late in the War by a scout sent into the Unknown Regions to discover another shipping route. The Confederacy of Independent Systems quickly took action with this new data.
Earth was unwillingly brought into the war when the CIS attempted to establish a hyperspace route through the system. At first, negotiations were attempted, but these quickly failed when Earth's governments realized they would be drawn into a much larger conflict. After this, the Separatists launched an Invasion of the Planet.
Many of Earth's governments were shattered and the armed forces were reduced to little more then militia fighting back against the droids. Aside from establishing the new hyperspace route through the system, the CIS began deporting many humans into slavery.
After roughly three standard months, the human population was reduced from seven billion to four billion. Around this time, Jedi Knight Keno Carti arrived on the planet, scouting it for the Jedi Council. He was shocked at the state of the planet and the suffering of the native humans.
The Jedi Knight quickly left the planet with a force sensitive named Colt Harding. Colt, a teenager, managed to convince the Jedi Council to help his planet. At least two Clone Legions were sent to the system, and in the battle managed to liberate the planet.
Following this, the planet and it's system was added to galactic charts as the Helios System. The planet was quickly brought into the Galactic Republic, just in time for Order 66 and the Republic to be reorganized into the Galactic Empire.
Under the Empire, Earth was once again suffering. However its time during the Clone Wars had prepared to fighting against Imperial Occupation. Earth became the Empire's version of Vietnam as it had one of the highest casualty rates for stormtroopers. This would make it the perfect place for escaped Wookie slaves and fugitive Jedi to hide.
As the Rebellion began to heat up in other parts of the galaxy, Earth and the Sol System in general became a major hotspot for conflict and a bastion of the rebellion. When the Rebellion finally captured Earth from the Empire, Darth Vader ordered the planet to be bombed. Even though the rebels were able to drive off the Imperial bombers, a large section of Africa and Europe was still reduced to rubble.
With Earth finally away from the major fighting, a rebuilding process began. Many of the native humans remained bitter against any droids and Imperials thanks to the conflict.
Later on Luke Skywalker and Colt Harding would establish a Jedi Outpost on the planet, allowing others to be selected and trained as Jedi.
Earth would once again become a hotspot for conflict during the Yuzhong Vong War as both the Jedi and Galactic Republic made a stand against the Invaders on the Planet.