Why go
The Seljuk victory at Manzikert in 1071 is a useful turning point when tracing Turkish settlement in Anatolia. Later Ottoman rule linked Anatolia to southeastern Europe, western Asia and North Africa. Understanding that sequence gives Istanbul's Ottoman landmarks a wider setting and shows why earlier Byzantine layers remain part of the same city's story.
The full story
Seljuk Turks entered eastern Anatolia in the eleventh century. Their defeat of Byzantine forces at Manzikert in 1071 opened a long period of change rather than an instant replacement of one culture by another. Turkish language and Islam spread gradually across a region that had many local traditions. The Seljuks also brought cultural influences shaped in Persia, adding another layer to Anatolia's heritage. After Seljuk power weakened, Turkish principalities emerged. One, associated with Osman I, grew into the Ottoman Empire. The Ottoman conquest of Constantinople in 1453 ended Byzantine rule in the city and made it a center of a much larger empire. Ottoman history stretched across Anatolia and far beyond it, so Istanbul's monuments reflect connections with several regions. The empire's defeat in the First World War led to its dissolution and a struggle over its former territories. The Armenian Genocide and massacres of Assyrians and Greeks were part of this violent final period; they should not disappear from the account when visiting sites tied to the empire's past.