Justice League: A Better World
The fascist police government of planet Thanagar tried to invade the Earth-50 in 2004 an event known as the Thanagarian Invasion. The Thanagarians first approached the Justice Lords with a propose for an alliance between both planets but it was rapidly found it was a ruse to move their fleet near Earth-50.
The hero known as Hawkman was the only one to oppose the Thanagarian Alliance because he was a former Thanagarian Hawkman police and knew they were bad news. At the last time, when the tide changed he was killed during the battle between the Justice Lords and the Typical Thanagarian Soldier. Heroes were killed during this event including the members of Infinity, Inc.. and Animal Man.
At a last attempt to win the invasion, the armies of Thanagar hired the services of galactic mercenary Mongul and his moon sized ship the Warworld. The Justice Lords gave the gigantic starship the same treatment as the Thanagarian Fleet and the Warworld had to flee with heavy damage.