Wikipedia
Muqata'ah
One of the most important topics of the Ottoman financial history is the institution of muqata'ah which functioned as an instrument in financing state expenses. The Ottoman bureaucrats of finance, by means of this institution, tried to meet state currency needs, raise loans in the interior and incorporate private entrepreneurship in the financing of the state.
The system of muqata'ah was a form of tax farming where a district or individual agreed to pay the state a fixed sum in return for fiscal autonomy and limited state intervention.