Bukhari

Hadith Commentary:
In another narration, it is stated: “This religion will remain honored until the time of twelve caliphs.”
In the narration of Abu Dawud, it is stated thus: “This religion will remain established until there are twelve caliphs over you, and all will be agreed upon.”
These twelve caliphs have already passed in the Ummah of the Prophet (sallallahu alayhi wa sallam).
From Hazrat Siddiq (radi Allahu anhu) up to Abdul Aziz (rahimahullah), fourteen individuals ruled.
Among them, the period of rule of two was very brief: one was Muawiyah bin Yazid, the other was Marwan.
If you exclude them, then there remain exactly twelve caliphs who held the caliphate with great strength and vigor.
After Umar bin Abdul Aziz (rahimahullah), the nature of the era changed, and the people did not gather around Hazrat Hasan and Abdullah bin Zubair (radi Allahu anhuma), but most people had already gathered before, so the caliphate of these two personalities is also rightful and valid.
The Imamiyyah have taken this hadith as evidence that twelve Imams are intended, i.e., from Hazrat Ali (radi Allahu anhu) up to Muhammad bin Hasan al-Mahdi. However, there is a doubt in this, for after Hazrat Hasan (radi Allahu anhu), people did not gather around any Imam, nor did they possess power and government; rather, most of them remained in hiding out of fear for their lives. So how can these people be intended by this hadith?
And Allah knows best.

Hadith Commentary:
1.
This narration of Sahih Bukhari is extremely concise because it does not mention the characteristics of the twelve caliphs; it only states that they will be from the tribe of Quraysh.
From other narrations, it is understood that during their rule, Islam will flourish greatly and will gain dominance, and those who oppose it will not be able to harm it.
(Sahih Muslim, Kitab al-Imarah, Hadith 4708(1821))
In this hadith, two additional points are mentioned which, from the perspective of chain of narration, are not authentic:
➊.
The Ummah will be united upon these caliphs.
➋.
After them, there will be killing and bloodshed, as Allamah al-Albani rahimahullah has written about this in detail.
(Silsilat al-Ahadith al-Sahihah, No. 376)
2.
There is much disagreement regarding the identification of these caliphs, therefore we have deliberately refrained from discussing this. However, the Shia claim that what is meant by them are their alleged twelve Imams, who begin with Ali radi Allahu anhu and end with Muhammad ibn Hasan al-Mahdi. But this is incorrect because, during their rule, Islam did not attain any glory or grandeur; rather, most of them remained in hiding to save their lives.
In our view, the Shia position is not based on reality.
And Allah knows best.