Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, بديع الزمان أَبُ اَلْعِزِ إبْنُ إسْماعِيلِ إبْنُ الرِّزاز الجزري, ældʒæzæriː) was a Muslim polymath: a scholar, inventor, mechanical engineer, artisan, artist and mathematician from the Artuqid Dynasty of Jazira in Mesopotamia. He is best known for writing The Book of Knowledge of Ingenious Mechanical Devices (كتاب في معرفة الحيل الهندسية) in 1206, where he described 50 mechanical devices, along with instructions on how to construct them. He is credited with the invention of the elephant clock. He has been described as the "father of robotics" and modern day engineering. Al-Jazari was born in the area of Upper Mesopotamia in 1136. Sources state his exact location is unknown, but they speculate he could have been born in Jazirat ibn Umar, where he got the name Jazari from or Al-Jazira which was used to denote Upper Mesopotamia. The only biographical information known about him is contained in his Book of Knowledge of Ingenious Mechanical Devices. Like his father before him, he served as chief engineer at the Artuklu Palace, the residence of the Mardin branch of the Artuqids which ruled across Upper Mesopotamia as vassals of the Zengid dynasty of Mosul and later of Ayyubid general Saladin. Little is known about his ethnic background, so he has been variously described as Arab, Kurdish or Persian. Al-Jazari was part of a tradition of artisans and was thus more a practical engineer than an inventor who appears to have been "more interested in the craftsmanship necessary to construct the devices than in the technology which lay behind them" and his machines were usually "assembled by trial and error rather than by theoretical calculation". His Book of Knowledge of Ingenious Mechanical Devices appears to have been quite popular as it appears in a large number of manuscript copies, and as he explains repeatedly, he only describes devices he has built himself. According to Mayr, the book's style resembles that of a modern "do-it-yourself" book.