original_query: What was the role of Sad ibn Ubadah ibn Dulaym in the early seventh century?
query: What was the role of Sad ibn Ubadah ibn Dulaym in the early seventh century?
answer: Sad ibn Ubadah ibn Dulaym was the chief of the Sa'ida clan of the Khazraj tribe in Medina. He later became chief of the whole Khazraj tribe and then of all the Ansar.  He was a prominent companion of Muhammad and attempted to become caliph after Muhammad's death.