Two pupils of Imam Abu Hanifa, Imam Abu Yusuf and Imam Muhammad, are known as Sahibain.'

They were Mujtahids in their own right due to their proficiency and expertise in :

1. Fiqh
2. Usul Fiqh
3. Tafseer
4. Usul Tafseer
5. Hadith
6. Ilm Hadith
7. Naaskih and Mansukh
8. Seerah
9. Lugha 
10. Balagha
    

Additional Information

Yaqub ibn Ibrahim al-Ansari known as Abu Yusuf

Abu Yusuf's personal name was Yaqub.

He was a student of jurist Abu Hanifah.