Excerpts from Books and Wikipedia
"Coupled with the rise of other Iranian dynasties in the region, the approximate century of Buyid rule represents the period in Iranian history sometimes called the 'Iranian Intermezzo' since, after the Muslim conquest of Persia, it was an interlude between the rule of the Abbasid Caliphate and the Seljuk Empire. . . . At its greatest extent, the Buyid dynasty encompassed territory of most of today's Iran, Iraq, Kuwait, and Syria, along with parts of Oman, the UAE, Turkey, Afghanistan and Pakistan. During the 10th and 11th centuries, just prior to the invasion of the Seljuq Turks, the Buyids were the most influential dynasty in the Middle East." [Wikipedia]