One David Alroy, claiming to be the Messiah, promises to lead the Jews and take Jerusalem from the Crusaders.

One evening he tells the Jews of Baghdad that they are all going to fly to Jerusalem that night and asks them to give him their property.

That night much of the Jewish population stands on their roofs waiting to fly.

According to Benjamin of Tudela, who visits a couple of years after the event, Alroy is slain, after one “successful” battle, by his father-in-law, who had allegedly been bribed and threatened by the governor of Amaida.

Alroy's followers call themselves Menahemites and continue to live in the Adzer Bedjan area.

They eventually fade out; Benjamin Disraeli's 1933 novel Alroy will become a well-known fictionalized version of Alroy's life.

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.)

Rabbi Benjamin of Tudela undertakes from 1160 to 1173 to survey the communities in the diaspora, traveling from Spain by way of Rome and Constantinople to the Near East, visiting most of the significant Jewish communities there.

In 1163, Benjamin finds forty thousand Jews residing in Baghdad, with twenty-eight synagogues and ten Torah academies.

In his Sefer Hamasot (Book of Travel), he describes the Jewish communities in Iran and India from the reports of eyewitnesses that he meets.

Benjamin, in describing his peregrinations in his “Itinerary,” is the first traveler to observe the existence of ancient ruins in Mesopotamia, a region whose pre-classical heritage had lain forgotten and unknown for many centuries.

Benjamin of Tudela, a Spanish Jewish traveler, reports that Constantinople in the late 1160s has merchant communities from Babylon, Canaan, Egypt, Hungary, Persia, Russia, Sennar, and Spain as well as two thousand Jews.