[9] The Buyid dynasty was founded by Ali ibn Buya, who in 934 conquered Fars and made Shiraz his capital.

His younger brother, Hasan ibn Buya (r. 935–976) conquered parts of Jibal in the late 930s, and by 943 managed to capture Ray, which he made his capital.

[23] Luckily for the Buyids, Mardavij was assassinated shortly thereafter in 935, which caused chaos in the Ziyarid territories, a perfect situation for the Buyid brothers; Ali and Ahmad conquered Khuzistan, while Hasan captured the Ziyarid capital of Isfahan, and, in 943, captured Rey, which became his capital, thus conquering all of Jibal.

After this, however, the Buyids went into a slow decline, with pieces of the confederation gradually breaking off and local dynasties under their rule becoming de facto independent.

However, Adud's other son, Shirdil Abu'l-Fawaris, challenged his authority, and the feared civil war occurred anyway.

[26] Meanwhile, a Kurdish Marwanid chieftain named Badh ibn Dustak seized Diyabakr and forced Samsam al-Dawla to recognize him as the vassal ruler of the region.

In 1029, Majd al-Dawla, who was facing an uprising by his Daylami troops in Ray, requested assistance from Mahmud of Ghazna.

[28] When Sultan Mahmud arrived, he deposed Majd al-Dawla, replaced him with a Ghaznavid governor and ended the Buyid dynasty in Ray.

During the beginning of the Buyid dynasty, their army consisted mainly of their fellow Daylamites, a warlike and brave people of mostly peasant origin, who served as foot soldiers.

The Daylamites had a long history of military activity dating back to the Sasanian period, and had been mercenaries in various places in Iran and Iraq, and even as far as Egypt.

[32] However, when the Buyid territories increased, they began recruiting Turks into their cavalry,[21] who had played a prominent role in the Abbasid military.

[39] Instead, Arabic served as the lingua franca of their realm, while Middle Persian was occasionally used as a secondary court language.

[3] The Persian vizier Sahib ibn Abbad (died 995), who was the leading figure at the Buyid court at Ray for a lengthy period, wrote only in Arabic, which he preferred instead of his native tongue.

[41] The Buyids also promoted the use of fahlaviyat,[40] a designation for poetry composed in the local northwestern Iranian dialects and languages.

[42][43] Due to having a large Zoroastrian and Christian population, many records written under the Buyids were composed in Middle Persian, Syriac and Arabic.

[13] Under the Buyids, the idea of "Iranshahr" (Iran) appears in geographical works, which were all written in Arabic by mostly Iranian authors.

The geographer Istakhri, who was active in the late 10th-century and wrote; "The best cultivated (ma‘mur), fairest and most fertile part of the world, and the most established in its political life is the kingdom of Iranshahr.

"[41] Herzig and Stewart adds that;[40] Considered together the preceding materials offer important clues to the question of Iranian identity under the Buyids.

[47] In addition, to prevent tensions between the Shia and the Sunnis from spreading to government agencies, the Buyid amirs occasionally appointed Christians to high offices instead of Muslims from either sect.

[48] Under the supervision of the Buyids, large construction and engineering projects took place, such as irrigation systems and agricultural developments, all of which led to an increase in income.

In comparison to other local rulers in Iraq, particularly the Baridis and Hamdanids, it was clear that the Buyids had a liking to construction projects.

When Mu'izz al-Dawla arrived in Iraq, the country had been ravaged as a result of local struggles over control of Baghdad.

Under his instructions, the Baduriya dam on the Rufayl river was restored, subsequently resulting in lower prices of common foods, such as bread.