Earth Civil war

"... and we've been unable to determine at this time how many have been killed on the recent attacks on Mars by Earth Gov. Forces. President Clark has announced that the attacks will continue until the Mars Provisional Government accedes to Martial Law. So far there's been no reaction from any of the outer colonies concerning these attacks..."
'I'm sorry, Jane. I'm sorry I jumped in like this, but we have to... the colonies at Orion 7 and Proxima 3, have just broken away from the Earth Alliance in protest over the bombing of Mars. They're setting themselves up as independent states until such time as President Clark is impeached. Clark doesn't want this information released but we have to go with this now cause we don't know how much longer we can stay on the air. Armed troops have begun moving in on the ISN Broadcast Center here in Geneva. We just saw them coming around the corner. We're trying to get a camera down there to document what's going on. I can hear gunfire now, up here on the fourteenth floor. Listen to me, there's information you don't have, that's been going on for the last year that we haven't been allowed to tell you...'
- ISN News Reporters, "Severed Dreams"

Because of this Proxima III, Orion VII and Babylon 5 declared their independence.

"May I have your attention please. In the last few hours we have learned that Warships are coming this way from Earth. Their orders are to seize command of Babylon 5 by force. As Commanding Officer and Military Governor of Babylon 5, I cannot allow this to happen. President Clark has violated the Earth Alliance constitution, by dissolving the Senate, declaring Martial Law, and personally ordering the bombing of civilian targets on the Mars colony. He is personally responsible for the deaths of hundreds of innocent people. Following these attacks, Orion 7 and Proxima 3, have broken away from the Earth Alliance and declared independence. Babylon 5 now joins with them. As of this time... Babylon 5 is seceding from the Earth Alliance. We will remain an independent state, until President Clark is removed from office. At the end of this current crisis, anyone who wishes to leave for Earth, is free to do so. Meanwhile, for your own safety, I urge everyone to stay in your quarters until this is over. That is all."
- Sheridan to the Station, "Severed Dreams"

Clark ordered Earth Alliance forces to seize control over Babylon 5. Shortly after the secession of Babylon 5 several Omega Destroyers and Hyperion Heavycruiser arrived in Babylon 5 space. Capt. Sheridan denied the hand-over of Babylon 5 to the loyalist Earth Alliance forces. Shortly after this both sides launched their fighters. Sheridan ordered not to fire first. He didn't want to start the fight but he wanted to end it.

Many people died when loyalist forces tried to get on board the station. It came to brutal fight between Earth Alliance forces and the Babylon 5 security teams. Finally the security teams managed to defeat the soldiers.

The first wave was destroyed by the two renegade Omega Destroyers Churchill and Alexander under the commands of Captain Sandra Hiroshi and Major Ryan. The Churchill was destroyed in this battle and the Alexander was heavily damaged.

It seemed to be a victory for Sheridan and the other renegade commanders when suddenly a second wave of loyalist forces arrived. This time there was no chance of wining the battle. Sheridan just wanted to surrender when Minbari Ambassador Delenn on board the WhiteStar arrived along with three Minbari Warcruiser.

"This is Ambassador Delenn of the Minbari. Babylon 5 is under our protection. Withdraw... or be destroyed."
'Negative, we have authority here. Do not force us to engage your ship.'
"Why not? Only one Human Captain has ever survived battle with a Minbari fleet. He is behind me, you are in front of me. If you value your lives... be somewhere else."
- Delenn and EA Captain, "Severed Dreams"

The Human commander of the Earth Alliance forces didn't want to risk a battle against the superior Minbari Cruiser and left Babylon 5 space