Re: Contributions of Umayyad Caliphate
It may or may not be true. I can’t make up my mind yet.
Abbasids never said that they are rising against Umayyads because they want revenge for Karbala. Instead their main point was that khilafat belong to Banu Hashim.
Most Muslims at that time agree with it. They got help from common people because they thought they will give khilafat back to Aal e Fatima. But when Abbasids got power then they said WE (Banu Abbas) are Banu Hashim and we have more right to khilafat compared to Aal e Fatima.
So they did use the slogan of giving khilafat back to its rightful heirs for political purpose, but they did not say that they are doing it due to Karbala.
I read somewhere that Abbasids did even worse atrocities than Umayyads.