Naming conventions The official names and the titles of the Medieval monarchs may be exterely long There are cases where the length of the official name may cover a whole page with father s and grandfater s names born and acquired names administrative religious and military titles epithets etc etc Well these names were used only in diplomatic letters and were never used widely In stead of these over elongated names the names of these people were always simple names made of only one or two word According to Wikipedia Wikipedia does not necessarily use the subject s official name but it uses the name that is most frequently used to refer to the subject If desired a section dediacated just to the names can be creted see Tardu So it is clear that Alp Arslan instead Diya ad Din Alparslan is preferred On the other hand the daughters of the monarchs are always given the title princess in Western languages So there is no need to add the title princess to the names of royal daughters