Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 10 months ago

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.