Books of History mention that Hazrat Abul Fazl Al-Abbas (a.s.) had 5 sons;
1. Obaydullah,
2. Al Fazl,
3. 3. Al Hasan,
4. 4. Al Qasim and
5. 5. Muhammad.
6. History also mentioned that he had 2 daughters. Mohammad Ibn Al-Abbas is mentioned as one of the Martyrs in Karbala.
Obaydullah son of Al-Abbas Ibn Ameerul Momeneen (a.s.) is been mentioned as the son who left children. All the grandchildren of Al-Abbas (a.s.) were from the sons of Obaydullah. The grand and great grand children of Al-Abbas (a.s.) are many and they include many Scholars and very pious Momeneen and very respected Personalities in the history of Muslims. Of the well-known personalities from the great grandchildren of Al-Abbas is Al-Hamza who is buried in Al-Midhatiyyah near Al-Hilla and the whole area is now is called after him as Al-Hamza.
Wassalam.