He was born in Qalaat Hammad, which is understood by most historians of the past 100 years to be Qalaat Beni Hammad in modern-day Algeria, capital city of the Hammadid rulers of central Maghreb. However, older sources believe Qalaat Hammad refers to a village near Fez. In the former case, Alfasi's name would indicate that his family had ancestry in Fez, an idea which is supported by the frequent reference to him as "ben Alfasi" or "ibn Alfasi" by the authorities closest to him in time and place. He studied in Kairouan, Tunisia under Rabbeinu Nissim ben Jacob, and Rabbeinu Chananel ben Chushiel the recognized rabbinical authorities of the age. Rabbeinu Chananel trained Alfasi to deduce and to clarify the Halakha from Talmudic sources, and Alfasi then conceived of the idea of compiling a comprehensive work that would present all of the practical conclusions of the Gemara in a clear, definitive manner. To achieve this goal, he worked for ten consecutive years in his father-in-law's attic.