Principal autonomy has been identified as an important ingredient in effective and healthy schools. However, little is known about the various dimensions of the phenomenon and how it takes form in different contexts. This article presents an analytical device contributing to further understand the complex nature of principal autonomy. The device follows the seminal work of Richard Ingersoll on autonomy in school organisations operationalised as decision-making and control. Moreover, we put forward a multidimensional device to organise decisions and control in several schooling domains: educational, social, developmental and administrative. By exemplifying the device on principals' perceptions of autonomy in the very North of Sweden, Norway and Finland, we can reveal important differences between the three Nordic neighbouring cases. Related to these reforms, principals' work can be compared in terms of different grades of complexity and risk, with corresponding consequences for their autonomy.