Muhammad dies in September 1041 while campaigning in Kurdistan against the Annazids.

His eldest son Faramurz succeeds him in Isfahan, while …

…his younger son Garshasp I gains Hamadan.

However, they have a difficult task in protecting these regions from the expansionist Seljuqs, who have become neighbors with the Kakuyids.

Tughril, the co-leader of the Seljuqs, makes Rey the capital of his kingdom after his defeat of the Ghaznavids.

Abu Harb, the third son of Muhammad, had rebelled against his older brother and called upon help from the Buyids of Fars.

Faramurz had defeated him, however.

Relations with Faramurz and Tughril are highly important.

It seems that Faramurz was present with the Seljuqs at the battle of Dandanaqan against the Ghaznavids.

When Faramurz ascended to the Kakuyid throne, Tughril had secured his allegiance by sending a tribute of payment to Faramurz.

However, neither Faramurz nor his brother Garshasp I are willing to turn to the side of Seljuqs.

In 1045, the Dailamites and Kurds of Jibal make a stand together to resist the advance of the Turkmens from Khorasan.

Tughril arrives to Isfahan, and Faramurz submits to the Seljuqs.

Around 1045-46, after Tughril's return to Khorasan, Faramurz declares himself independent of Seljuq rule, and submits to the Buyids, forcing Tughril to return to Isfahan, where he defeats the Kakuyids, and makes Faramurz his vassal once again.