1954, Ann K.S. Lambton,Theory and Practice in Medieval Persian Government, page243:
While the sultan thus hoped to retain the nominal allegiance of the great amīrs through theatabegate, they, on the other hand, saw in it a means to establish their virtual independence.
A closer parallel was theatabegate in the powerful medieval Turkish dynasty of the Seljuks, centered in Iran. Theatabeg (Turkish for "father-governor") was the Seljuk possessor of thelala; in fact, the Ottomans sometimes used the two terms interchangeably.