Baha' al-Dawla

Baha' al-Dawla (died December 22, 1012) was the Buyid amir of Iraq (988–1012), along with Fars and Kerman (998–1012). His early reign was dominated by struggles with his rival relatives over control of the western Persian provinces, but by 998 he managed to establish his supremacy over the Buyid confederation. His reign nevertheless saw the increasing encroachment of neighbouring powers on Buyid territory, and marks the beginning of the decline of the Buyids' power.

Biography
He was the third son of 'Adud al-Dawla.

Upon the death of his brother Sharaf al-Dawla in 988, Baha' al-Dawla succeeded him, whereupon he took the additional title of Diya' al-Milla. Another brother, Samsam al-Dawla, prevented Baha' al-Dawla from gaining all of Sharaf al-Dawla's possessions by taking control of Fars, Kerman and Khuzestan. Both Baha' al-Dawla and his brother, however, were threatened by their granduncle Fakhr al-Dawla, the ruler of Jibal, who invaded Khuzestan in an attempt to drive a wedge between the two brothers' territories. This act prompted the brothers to draw up an alliance. Samsam al-Dawla recognized Baha' al-Dawla as the ruler of Iraq and Khuzestan, while he himself kept Arrajan, Fars and Kerman. Both promised to consider each other as equals, and took the title of king (malik).

In 991 Baha' al-Dawla attempted to gain supremacy over Samsam al-Dawla's realm. He took the ancient Persian title of Shâhanshâh and invaded the latter's territory. His forces were defeated, however, and Samsam al-Dawla regained Khuzestan and even gained control of the Buyid territories in Oman. He then recognized Fakhr al-Dawla as senior amir, submitting to his authority.

Fakhr al-Dawla's death in 997, coupled with Samsam al-Dawla's increasing troubles within his realm, provided Baha' al-Dawla with the opportunity to assert his authority in Persia. He gained the support of the Kurdish ruler Badr ibn Hasanwaih and prepared for the expedition. The invasion began in December 998; scarcely had it commenced when Samsam al-Dawla was killed by one of the sons of 'Izz al-Dawla who had risen in revolt. Baha' al-Dawla then took Shiraz and defeated 'Izz al-Dawla's sons. For the rest of his life Baha' al-Dawla remained in Fars. He also managed to gain indirect control over northern Iran, where Fakr al-Dawla's two sons Majd al-Dawla and Shams al-Dawla recognized him as senior amir by 1009 or 1010.

Baha' al-Dawla's reign coincided with the beginning of the decline of the Buyids. The Kurdish chief Badh laid the foundations for the Marwanid amirate in Diyarbakr, while the initially subservient 'Uqaylids of Mosul expanded into Iraq at the Buyids' expense. By the time Baha' al-Dawla died, Baghdad and Wasit were the only two major Iraqi cities directly under his control. In the north, where Fakhr al-Dawla's sons ruled, the Buyid frontier also fell back, as the Ziyarids of Gorgan and Tabaristan permanently wrested themselves from Buyid control. The Ghaznavids kept putting pressure on the Khurasan border, while the Kakuyids began to set up a state in Isfahan.

For various reasons, Baha' al-Dawla did not actively defend the borders. Having gained undisputed control of the Buyid state, he seemed content to allow external enemies to seize territories in the west and north. He died in Arrajan in December of 1012. Shortly before his death, he named his son Sultan al-Dawla as his successor.