Benjamin of Tudela, in his ambitious journey…

Benjamin of Tudela, in his ambitious journey to visit the Jewish communities of the diaspora, misses only that of Kaifeng, in China, where a colony from India or Persia had settled probably in about 1127, building a synagogue—the oldest known in China—in 1163.

(An extant stone tablet dated 1512 and found in K'ai-feng claims that Judaism entered China during the latter half of the Han dynasty, i.e., before CE 220, but the authenticity of the tablet is disputed.)