In 1905, the Islamic reformer Rashīd Riḍā published in his journal al-Manār a response to a question posed to him by a reader in Singapore. It concerned the marriage of a sayyida from the Ḥaḍramī community in South East Asia. The marriage had been publicly denounced by the Ḥaḍramī ʿAlids because of its unsuitability: The groom was an Indian Muslim of non-sayyid descent. Rashīd Riḍā sanctioned the marriage, arguing that there was nothing in Islamic law to prohibit it. Riḍā's opinion was strongly contradicted by the leading Ḥaḍramī scholar of the time, Sayyid ʿUmar al-Aṭṭās, who declared that a marriage between a sayyida and a non-sayyid was unlawful, because descent was the basic criterion for suitability in marriage (kafāʾa). He identified four levels of kafāʾa: Arabs must not marry non-Arabs; Qurashīs must not marry non-Qurashīs; Hāshimites must not marry non-Hāshimites; and descendants of Hasan and Ḥusayn must not marry anyone other than Ḥasanids or Ḥusaynids. The discussion went back and forth for some time and eventually sparked a power struggle in the overseas Ḥaḍramī communities that had long adhered to a rigid system of social stratification based on descent. People began to question openly the centuries-long domination of the sayyids, their status and their system of social control, setting in motion events that arguably led to the Yemeni revolution and the abolition of the Zaydī imāmate in 1962.