In 222 BC, the last remnants of Yan and the royal family were captured in Liaodong in the northeast. The only independent country left was now state of Qi, in the far east, what is now the Shandong peninsula. Terrified, the young king of Qi sent 200,000 people to defend his western borders. In 221 BC, the Qin armies invaded from the north, captured the king, and annexed Qi. Some of the strategies Qin used to unify China were to standardize the trade and communication, currency and language.