He remained like this till he died in his bed.

He remained like this till he died in his bed." (AI-Mas'udi; in Muruj al-Dhahab, Vol.3, p.226) The main theme of this address was that Muhammad Nafs al-Zakiyya had no claim of Khilafat because his great-grand-father, Imam Hasan, has relinquished this power.

Accordingly, he wrote a letter to Muhammad who was still at large and was gathering an army to fight against Mansur: "The Khilatat of your ancestor (Ali) reached to Hasan; he sold it to Mu'awiya in consideration of money and cloth Now, if you had any right in the Khilafat, you had already sold it and received its price." But Mansur knew that this line of argument solved only the immediate problem of the bay'a of Muhammad Nafs al-Zakiyya.

It could not prevent one of the descendants of Imam Husain from claim to the Khilafat for himself. Therefore, he left no stone unturned to prove that the Fatimids were not entitled to the inheritance of the Holy Prophet at all; and that Bani' Abbas were the rightful heirs of the Holy Prophet.

In Arabia, prior to Islam, inheritance "was governed by the rule of agnacy." It means that only those persons who were connected with the deceased 'through males' were recognised as entitled to take a share in his inheritance (they are called 'agnatic relatives'), and neither women nor persons connected to the deceased through them had any right of succession, (they are called 'uterine relatives').

"Thus it was that whilst adopted sons and even slaves had rights, the children of daughters and sisters had no place in the customary rules which regulated succession." (Ameer `Ali in 'Mohammedan Law', Vol.2, p.75) Islam put an end to such affront to human nature, and in the Qur'an there are specific provisions for the succession of daughters, mothers and sisters. But Mansur, in rank defiance of the Qur'an, revived the old custom of agnacy.

Ameer `Ali writes: "When the Abbasids succeeded in overthrowing the Omeyyads, they found it necessary to legitimatise their title to the Caliphate, for the eyes of the Moslem world were still turned to the descendants of the Prophet as the rightful heirs to his temporal and spiritual heritage and in effecting this they found their chief support in the doctrine of agnacy.

They claimed that as descendants of the Prophet's uncle, Abbas, they were his 'agnates' and as such had a better title than the descendants of his daughter Fatima.