QALʿAT ḤAMMĀD, city formerly situated S.W. of *Constantine, *Algeria. It was founded in 1007 by a branch of the *Zirids (Banu Zīrī) who reigned in *Kairouan. Its population included Christians, Jews, and members of the Jerāwa tribe, *Berbers formerly converted to Judaism. Qalʿat Ḥammād received the majority of the inhabitants of Kairouan when that city was sacked by Arab nomads in 1057, and it inherited the importance of the former metropolis. As capital of a vast kingdom in the 11th century, it possessed a Jewish elite among whom was Solomon ha-Dayyan b. Formash. Abraham *Ibn Daud knew of Solomon and also reported the tradition which stated that Isaac *Alfasi was born in Qalʿat Ḥammād. The city was completely destroyed by the *Almohads in 1152.
Neubauer, Chronicles, 1 (1887), 73, 75; L.M.E. de Beylie, La Kalaa des Beni-Hammad (1909); Poznański, in: REJ, 58 (1909), 297–8; Hirschberg, Afrikah, 1 (1965), 167, 259.