In fact, it's viewed as the first dynasty since the Sassanids that actually had native Persian rule and brought back that Persian culture, part of which is using the word Shah. You remember Cyrus the Great, the Shah and Shah, the king of kings. Now, they had what is known as gulams, which is very similar to the idea of a janissary. These are slave soldiers which are taken as captives but then are raised to be an elite military unit and eventually often have significant wealth and significant power. Now, you might be wondering why did any of these empires, and these aren't the only ones. You have the Mamluks in other Muslim empires. Why would people create these elite soldiers out of slaves and give them that much power?