ABU YUSUF ابو يوسف
Known also an Ya’qub ibn Ibrahim. Born at Baghdad, A.H. 113. Studied under the Imam Abu Hanifah, and is celebrated, together with the Imam Muhammad and the Imam Zufar, as disciples of the great Imam; from whose opinions, however, the three disciples not unfrequently differ as will be seen upon reference to the Hidayah He died in A.H. 182.
Based on Hughes, Dictionary of Islam