in the late 930s, and by 943 managed to capture Ray, which he made his capital. Hasan was given the laqab of Rukn al-Dawla . In 945, the youngest brother, Ahmad ibn Buya, conquered Iraq and made Baghdad his capital. He was given the laqab Mu'izz al-Dawla.

As Iranians of Daylamite origin, the Buyids consciously revived the symbols and practices of the Sasanian Empire.