Al-Kindi

Al-Kindi (c. 801-873 CE) was an Arab philosopher and polymath active in the Abbasid court in Baghdad, often called the father of Arab philosophy for his role in introducing and adapting Greek philosophical thought into the Islamic intellectual tradition. Beyond philosophy he wrote on mathematics, medicine, music theory, meteorology and optics, and his treatise on deciphering cryptographic messages, which describes frequency analysis as a method for breaking substitution ciphers, is the earliest known text on cryptanalysis. He also directed a group of scholars translating Greek scientific and philosophical texts into Arabic, work that helped preserve and transmit classical learning. Several hundred works are attributed to him across nearly every branch of the sciences known in his time, though only a fraction survive intact.