The Chronicles of Restoring the Tang Dynasty

During the Tianbao era, the An brothers rebelled, and their forces swept across the land. The imperial armies suffered defeat after defeat, unable to quell the rebellion. With no other choice, the emperor issued an edict calling on the lords across the realm to come to his aid, allowing them to recruit their own troops. And so, chaos descended upon everyone without warning.

Zhang Luo, a soul from a later age, was initially delighted. Having transmigrated into a scion of a prominent family, he seemed to have a life of decadent luxury waiting for him. Our Great Tang has its own circumstances, so what's wrong with me enjoying myself?

Then he realized something was off. Why was the Great Tang's Gaozu called Li Dong? And why were the provincial governors called regional commanders?

Where on earth have I ended up? Is this even China?