Abraham ben Jacob was born in the year 912 or 913. He was a traveler as well as a Jewish-Arab merchant from Tortosa, Spain.
Abraham ben Jacob wrote about Poland in the accounts of his trip to Germany and the Czech Republic. He calls Poland the land of Mieszko I and names Kraków as Karako. It is the first mention of Krakow in written sources, as well as an important source for researching Polish history from the times of Mieszko I. Abraham ben Jacob writes about Krakow that it is the central stronghold of a larger area of great commercial importance. He also emphasizes that the journey from Prague to Krakow takes three weeks.
This travel account is preserved in the work of the Spanish-Arab geographer el-Bekri from the 11th century.