GATE: Thus Versellia empire fought there

75,000 years ago, 4 ships full of convicts and prisoners suddeny went through the portal and crashed the ships on the desert planet. However, Convicts and Prisoners decided to created their own civilizations with advanced technologies. However, They're will have to suffer by war in the planets were humans battle each other for resources and fight for the last man. But the war ended with 35,000,000 dead and many died by an harsh environment. The population comes together and created their own nations with new technologies. There's also explores to spaces and colonies the two moons and other planets. The versellia empire was one of them and has a best military in the world. However, Their peace is shattered when the gate suddenly open in the capital and roman-like soldiers attack them. By they're were easily beaten by the advance army. The empire has send the military through the gate and explore it. But they're will meet the JSDF from alnus hill. How will the JSDF and the rest of the world react this?