Murdoch, in his History of Japan (vol. i. p. 146), thus describes the greatness of the early Tang Empire:
"In the following year (618) Li Yuen, Prince of T'ang, established the illustrious dynasty of that name, which continued to sway the fortunes of China for nearly three centuries (618-908). After a brilliant reign of ten years he handed over the imperial dignity to his son, Tai-tsung (627-650), perhaps the greatest monarch the Middle Kingdom has ever seen. At this time China undoubtedly stood in the very forefront of civilization. She was then the most powerful, the most enlightened, the most progressive, and the best governed empire, not only in Asia, but on the face of the globe. Tai-tsung's frontiers reached from the confines of Persia, the Caspian Sea, and the Altai of the Kirghis steppe, along these mountains to the north side of the Gobi desert eastward to the inner Hing-an, while Sogdiana, Khorassan, and the regions around the Hindu Rush also acknowledged his suzerainty. The sovereign of Nepal and Magadha in India sent envoys; and in 643 envoys appeared from the Byzantine Empire and the Court of Persia."
Cordier, op. cit. ii. p. 212.
Cordier, op. cit. ii. p. 339.
Cordier, op. cit. i. p. 484.
The Truth About China and Japan. George Allen & Unwin, Ltd., pp. 13, 14.