Final answer:
The Chandraat majalis were not established by any listed group; such gatherings are culturally variational within the wider Muslim community. The Fatimid dynasty established the only Shia caliphate, emphasizing the Shia Islamic principle that leadership should be from the Prophet Muhammad's descendants.
Step-by-step explanation:
The Chandraat majalis were not established by any of the listed Islamic groups directly. The term "majalis" typically refers to gatherings or sittings, which are often religious in nature. Shia Muslims, in particular, have a tradition of holding majalis to commemorate various religious events, such as those during the month of Muharram for the martyrdom of Imam Hussain, a key figure in Shia Islam. In this context, Chandraat refers to the night of the moon sighting that marks the end of the Islamic month and beginning of the next, a time which does not have a specific type of majalis associated with it universally across Muslim traditions. However, various cultural practices may include gatherings on this night among different Muslim communities, but these are not foundational practices established by a particular group.
Regarding the only Shia caliphate, the Fatimids established the only Shia caliphate. They were a dynasty that ruled parts of the Mediterranean and prioritized Shia Islamic principles. The Fatimid Caliphate played a significant role in the history of Islam, having established their rule and their own caliphate in contrast to the Sunni Abbasid and Uma-yyad caliphates.
The Shia are those who believe leadership should reside with descendants of the Prophet Muhammad, specifically through his son-in-law Ali. The primary disagreement between Sunni and Shia Muslims after the death of the Prophet Muhammad was over rightful leadership, which led to the major schism within Islam. The Sunnis represent the majority group who believed that leadership did not need to come specifically from the Prophet's family, opting for a more community-driven selection process for leaders.