CEVAP:

After a decisive battle in 1040 CE the Seljuks were victorious and became the regional power for Persia and Central Asia in the Abbasid Khalifate. Within a few years the Seljuk leader had gained control over Baghdad, where he greatly impressed the Abbasid leaders and was brought into an alliance with their Khalifate to replace the Buyid’s as the local governmental apparatus. It was at this time that the Seljuk leader was given the title of Sultan by the Abbasid Khalifa.