His Turkmen followers, numbering 4,000 tents, then sought permission from Mahmud to settle on the northern edge of Khurasan in the districts of Sarakhs, Ablvard and Farava, where they promised to act as frontier guards. The decision to admit these lawless elements, who as pastoral nomads could not be expected to have any regard for agriculture and settled life, was later recognized by the sultan to have been a mistake.
In 418/1027 Mahmud had to send a punitive expedition against them, the people of Nasa and Ablvard having complained about their spoliations. But his general Arslan Jadhib failed to master them, and in the next year, the sultan himself came and inflicted a crushing defeat on the Tiirkmens, scattering them broadcast. Some fled westwards into the Balkhan Mountains on the eastern shore of the Caspian. Others fled into the interior of Persia, where they successively sought employment as mercenaries: first with the Buyid Qawam al-Daula of Kirman, then with the Kakuyid ruler of Isfahan, 'Ala' al-Daula, and finally with the Rawwadid amir of Tabriz, Vahsudan b. Mamlan, who aimed to use them against his rivals the Shaddadids of Arran and against the Christian Armenian and Georgian princes. It is these Tiirkmens who are called in the sources the " 'Iraqi" ones, because they had entered 'Iraq 'Ajami, i.e. western Persia.
They do not seem to have had any outstanding leaders, and deprived of Arslan Isra'il's leadership, they split into undisciplined bands. Eventually, they joined up with other Oghuz who, if the accounts of an expedition under Chaghri Beg as far as Azarbaijan and Armenia at some time between 407/1016-17 and 412/1021 are to be credited, had entered northern Persia a few years previously.