Abu Ahmad al-Husayn ibn Musa al-Musawi was a prominent Alid who held senior offices for the Buyid dynasty in Baghdad in the late 10th/early 11th century, and the father of the Twelver Shi'a scholars al-Sharif al-Murtada and al-Sharif al-Radi.

Al-Husayn was a Musawid, a descendant of the Shi'a imam, Musa al-Kazim (d. 799).^[1] He had three sons: Abu Muhammad al-Qasim, Abu'l-Qasim Ali, known as al-Sharif al-Murtada, and Abu'l-Hasan Muhammad, better known as al-Sharif al-Radi.^[1]

Al-Husayn was the first member of his family to be appointed as dean of the Alids (naqib al-ashraf) by the Buyid emir of Iraq, Mu'izz al-Dawla (r. 945–967), on 7 June 965.^[2] The post also entailed the supervision of the Hajj pilgrim caravans, until 970, when it returned to the responsibility of the Banu Yahya family of Kufa.^[3]

As descendants of Musa, al-Husayn and his family were Twelver Shi'a,^[4] which caused reactions among some of the Alids, accustomed to be led by a member of the Hasanid line; as a result, some Alids refused to recognize his authority and asked to be exempted from it.^[5] Al-Husayn established a good and close relationship with the new emir, Izz al-Dawla (r. 967–978), who kept him in office and assigned him in 968/9 to mediate between the Hamdanid emir of Mosul, Abu Taghlib, and his younger half-brother Abu'l-Muzzafar Hamdan.^[5] After riots erupted in Baghdad in 971, al-Husayn was dismissed, but still retained the favour of Izz al-Dawla, who entrusted him with the peace negotiations with the Hamdanids in 972/3.^[2]

When Adud al-Dawla (r. 943–983) first seized Baghdad in 975, al-Husayn was restored as naqib al-ashraf in August/September,^[6] and retained by Izz al-Dawla after his return to the city, and again by Adud al-Dawla when he finally took control of Iraq in 978. More than that, al-Husayn was appointed to lead the conquest and pacification of formerly Hamdanid Upper Mesopotamia, which he successfully carried out in 978–979.^[7] Once Adud al-Dawla's position was secure, however, he did not hesitate to strike against the incumbent elites of Iraq: in August /September 979, al-Husayn was accused of embezzlement and deposed, and exiled along with his brother, Ahmad, to Fars.^[8] The Zaydi-leaning Alid Muhammad ibn Umar, and the chief qadi and friend of al-Husayn, Ibn Ma'ruf, also fell victim to this purge, and were banished to Fars.^[9] The exiles were released from confinement after the death of Adud al-Dawla in 983, but remained in exile in Fars until 987, when the Buyid emir of Fars, Sharaf al-Dawla (r. 983–988/9), also seized control of Iraq.^[10] The 12th-century historian Ibn al-Jawzi claims that al-Husayn was reappointed as naqib al-ashraf, until he resigned in September 989 due to illness, but this is not corroborated in other sources.^[11]

Al-Husayn was reappointed as naqib al-ashraf by Baha al-Dawla (r. 988–1012) in May/June 990. In addition he received responsibility for civil courts (mazalim).^[12] His two sons, al-Radi and al-Murtada, were appointed as his deputies.^[13] At about the same time, a fierce rivalry developed between al-Husayn and his family and the pro-Zaydi Muhammad ibn Umar, who was imprisoned in the ensuing purge.^[14] Al-Husayn was high in favour with Baha al-Dawla, who entrusted him with an embassy to the Uqaylids in 992/3, during which he was imprisoned by the Uqaylid emir Muhammad ibn al-Musayyab. In January 994 al-Husayn was the legal guardian (wali) for Baha al-Dawla's daughter during her wedding with Caliph al-Qadir.^[14] A change in government however brought another dismissal, as the new Buyid vizier, Shapur, was a partisan of Muhammad ibn Umar, whom he released from imprisonment. In December 994, al-Husayn was replaced in his offices by a Zaydi candidate.^[15]

Al-Husayn nevertheless managed to restore his standing, for by 999 he was sent by Baha al-Dawla to accompany his troops during the capture of Shiraz.^[16] In 1003/4, after the death of Muhammad ibn Umar, al-Husayn was re-appointed to his previous position.^[16] To this was now added the post of chief religious judge (qadi), but his well-known Shi'a leanings and lack of previous service as a qadi in Baghdad aroused the opposition of the Sunni populace and Caliph al-Qadir; the appointment was consequently of short duration.^[17]

Al-Husayn died in 1009/10.^[18] He was succeeded by his son al-Radi, and after the latter's ddeath in June 1015 by another son, al-Murtada.^[19]