After Guarding the Border for Five Years, the Emperor Used a Jade Seal to Smash Walnuts for Me!

Once Zhao Si traveled through time, his mother and concubine died early, his maternal family had no rights, and he was all alone. He has no ambitions, neither wants to dominate the world, nor does he want to be the next unlucky emperor to die early. Fortunately, he is a prince and can ask to guard the border! Being a carefree emperor in the fiefdom, raising flowers and teasing dogs, making cement firearms, and making some glazed crossbows. When bored, you can catch the most beautiful girl in the prairie and come back to dance. While crying about poverty with the emperor's father, he secretly built the fiefdom and made it impregnable. Concrete city walls rising from the ground, giant repeating war crossbows, cement roads with eight vehicles traveling abreast, countless hidden intelligence networks... It's another sunny day, Zhao Si. Lying on the toffee chair under the grape trellis, leisurely eating grapes and flirting with the maid, suddenly someone came to report: "The emperor is here!" Zhao Si's happy and beautiful life ended...