During the early 14th century, Song China finally fell apart into four states; one of them, Hong China, prevailed and even conquered its competitors in the South, the Jin, plus several other smaller states, like Dali and Annam. Other states in East and SE Asia became China's allies and tributaries. Chinese influence and culture (incl. Confucianism) spread again, and with their treasure fleets brought the tales of China even as far as Egypt.
After some centuries, they declined however; their former satellites in SE Asia became independent again. Time was ripe for a new dynasty, which came in 1789 with the general Lin Xiaolong, who introduced a new Russian invention, the telegraph, and took power as emperor Yongzhi. The Hong fled to Tungning (OTL Taiwan), coming under British and later Canadian influence.
Ming China became a great power again, but in the 2nd half of the 19th century, their dynasty suffered the same fate when the growing population joined the Orthodox-influenced "Society of Brotherly Love". The country detoriated and even saw the Russians taking Beijing and most of the north of the country. Finally however, a general took power, reunited China and formed it into the Adoptive Empire.
The adoptive emperors restored Chinese greatness again and liberated the north during World War I. Afterwards, however, they faced problems with unrest in occupied Nippon and a struggle in influence with Germany and its ally Canada.