The Permanent Committee for Scholarly Research and Verdicts were asked the question:

The second question from fatwa no. (6363): The Prophet (sallallaahu alayhi wasallam) said: "The khilaafah after me is thirty years, then there will be biting kingship" and for this reason Mu'aawiyah said, "I am the first of the kings", from the risaalah of Abi Zayd al-Qayrawaanee (1/96). What is the meaning of this hadeeth?

And their response:

This hadeeth has been related by Imaam Ahmad in al-Musnad, al-Haakim in al-Mustadrak, Abu Ya'laa in al-Musnad, Ibn Hibbaan in his Saheeh and at-Tirmidhee in as-Sunan. And the meaning of the hadeeth has been explained by al-Haafidh (Ibn Hajar) in al-Fath, he said:

He meant by the khilaafah, the khilaafah of prophethood (i.e. the thirty years), and as for Mu'aawiyah and whoever came after him, then they were upon the way of the kings (i.e. kingship) even if they are named "khalifahs (successors)".

And with Allaah lies success. May prayers and salutations be upon our Prophet Muhammad, his family and Companions.

Permanent Committee for Scholarly Research and Verdicts

1. Abdul Azeez ibn Abdullah ibn Baz
2. Abdul-Razzaq Afify
3. Abdullah ibn Ghudayyan
4. Abdullah ibn Qu'ood

This answers the shubhah (doubt) that may arise when coming across references made by the people of knowledge in the course of historical reference and discussion to some of the rulers who came afterwards as "khalifahs", for even if they are named "khalifahs", it does not change the reality of the mode of rule present being through kingship. Such "khalifahs" were "successors" in kingship, so calling him a "khalifah" does not change the mode of rule, since the word "khalifah" simply means "successor", and whilst they were "successors" in the mode of rule of kingship, Abu Bakr, Umar, Uthmaan and Alee (radiallaahu anhum) were "khalifahs (successors)" in Prophetic khilaafah.