The Banu Qurayza (بنو قريظة‎‎) were a Jewish tribe which lived in northern Arabia, at the oasis of Yathrib now known as Medina, until the 7th century, when their conflict with Muhammed led to their extermination. Jewish tribes reportedly arrived in Hijaz in the wake of the Jewish-Roman wars and introduced agriculture, putting them in a culturally, economically and politically dominant position. However, in the 5th century, the Banu Aws and the Banu Khazraj, two Arab tribes that had arrived from Yemen, gained dominance. When these two tribes became embroiled in conflict with each other, the Jewish tribes, now clients or allies of the Arabs, fought on different sides, the Qurayza siding with the Aws.