The first Kaiju that came to Serbia, code named "Usud", reached the shores of Montenegro through the Adriatic Sea. Kaiju attacks were usually limited to cities along the Pacific Rim, and this sudden attack was not something anyone expected. Usud came through Montenegro, stomping anything that was in his path. Having no Jaegers, and limited firepower, Serbia and the surrounding country's could not stop the monster. Fearing that the Kaiju will progress even further inland, before any Jaeger came to stop it , NATO decided to bomb the Kaiju with nuclear weapons. After four nuclear missiles, the Kaiju finally stopped, but at a great cost. Belgrade, the capital of Serbia, and all the major cities Usud came through were reduced to ruble, and the radiation from the nukes and the kaiju blood poisoned what was left. A great number of people retreated up north of Serbia, to Vojvodina and it's capital, Novi Sad. Fearing that something like this could happen again, Serbia joined in building the Anti-Kaiju Wall, and also started building their own Jaeger. Russia played an enormous part in building the mech, providing plans and resources it could spare. Vojvodina, once a fertile land, was soon made into a industrial country of it's own. The Jaeger was built in the industrial zone "FEKETIC", named after a small village that was once there. After the Jaeger was build, it was put to guard the Anti-Kaiju Wall's checkpoint, the Petrovaradin fortress, in Novi Sad. It was soon named "PETROVARADIN", after the fortress itself.