Is it possible this was a family from Baghdad or Kufa (in the Persian Sassanid empire) which is why the Caliph established his caliphate there?
Thanks.
The question of why Imam Ali a.s. has moved the capital to Iraq has been contemplated by Muslims since the Early days.
The answer can be anticipated based on a saying by Imam Ali a.s. himself.
In Al-Imamah Was-Siyasah (Immamate and Politics) by the early Sunni Scholar, Ibn Qutaiba. The following is mentioned.
وقال عليه السلام حينما نصحه ابن عباس بأن يولي طلحة والزبير الكوفة والبصرة: "ويحك، إن العراقين بهما الرجال والأموال، ومتى تملكا رقاب الناس يستميلا السفيه بالطمع، ويضربا الضعيف بالبلاء، ويقويا على القوي بالسلطان
Here is my quick translation:
When Ibn Abbas asked Imam Ali to appoint Talha and Zubair as governors of Kufa and Basra (Iraq) he ( the imam a.s.) said: Wow to you, the two Iraq(s) contain the men and the wealth
.
So Imam Ali sees the demographic and the economical side of the decision
Surely he also sees the religious and the political sides, where After 25 years of being ruled by the other Caliphs, Medina has been influenced in way that is not in favour of Imam Ali a.s.
Also, Iraq is geographically close to Sham, where Moaawiyah declared his opposition to Ali a.s
.
Finally, we have to remember that it was a time turmoil and wars
We also need to consider who imam ali a.s. is
Thanks