What areas did the Seljuk Turks control by the end of the 11th century? What empire were they encroaching on? What was significant about their leader calling himself a Sultan?

a) Outline the territorial extent of the Seljuk Turks by the end of the 11th century.
b) Identify the empire that the Seljuk Turks were encroaching on.
c) Analyze the significance of the leader adopting the title Sultan.
d) Provide a historical con for the Seljuk Turks' impact on the region.