EBN ŠĀHAWAYH (Šāhūya), ABŪ BAKR MOḤAMMAD b. ʿAlī, a leader and envoy of the Carmatians. In Šawwāl 366/May-June 977 he occupied Kūfa at the head of 1,000 Carmatians supporting the claim of the Buyid Ażod-al-Dawla to the rule of Iraq against that of his cousin ʿEzz-al-Dawla. Later he became the permanent representative of the Bahrain Qarmaṭīs to the court of Ażod-al-Dawla. In 369/979-80 he was sent by ʿAżod-al-Dawla from Hamadān on a mission to Baṣra but soon returned to his court. No doubt for political reasons, Ażod-al-Dawla maintained close relations with him. Ebn Šāhawayh is described as a friend of Ażod-al-Dawla’s vizier ʿAbd-al-ʿAzīz b. Yūsof, of the Qāżī Abū ʿAlī Tanūḵī, and of Ṣāḥeb b. ʿAbbād, then vizier of ʿAżod-al-Dawla’s brother Moʾayyed-al-Dawla in Ray. After the death of ʿAżod-al-Dawla in 372/983, Ebn Šāhawayh became the representative of the Carmatians at the court of Ṣamṣām-al-Dawla in Baghdad. He had close ties with Ebn Saʿdān, appointed vizier by Ṣamṣām-al-Dawla in 373/983. In 374/984 he was in Oman and persuaded its governor to change his allegiance from Šaraf-al-Dawla to his brother and rival, Ṣamṣām-al-Dawla. Later in the year, Ebn Saʿdān and his friends, including Ebn Šāhawayh, were arrested; Ebn Saʿdān’s close relations with the Carmatians may have contributed to his fall, since the latter apparently were shifting their support at this time to Šaraf-al-Dawla, who had also quickly regained control over Oman. When Ebn Saʿdān and his companions were executed in 375/985, Ebn Šāhawayh was overlooked. He was soon released and restored to a position of honor by the vizier Abu’l-Rayyān. The same year the Carmatians of Bahrain occupied Kūfa and proclaimed Šaraf-al-Dawla the ruler, giving the imprisonment of their representative as a pretext. Abu’l-Rayyān now employed Ebn Šāhawayh as his intermediary with the invaders. Shortly afterward the Carmatians suffered a disastrous defeat which broke their power in Iraq permanently. Ebn Šāhawayh evidently also lost his influence, and there is no more mention of him thereafter in the sources.