The Abbasid's strategically chose Turks to be their personal bodyguard and called them Mamluk. They didn't find it safe for the Arabs or Persians to guard them. The Arabs were disappointed at them and the Persians always had a clash with the Arabs. These Mamluk were huge in number as the Abbasid felt the need for extra security as most kings do. However, their strategy backfired on them. These Turk bodyguards were well trained in combat by the Abbasid. Abbasid had such a huge land to rule that they lacked giving proper attention to all the land. The Mamluks took advantage of the situation and slowly started their own ruling starting with Mahmud a Mamluk general who called himself the Sultan and established his capital in Ghazni near Kabul. And slowly they grew and eventually became a total power over the Khilafah. This transmission of power is very interesting. It seemed that at the time Muslim rulers were more worried about power and personal economy rather than being a spiritual leadership. And that is why three separate Islamic states were in co-existance.