The lower judicial and administrative authorities of the Dubrovnik Republic were organized in two types of administrative units: captaincies and districts. The size of the territory and the number of captaincies and districts changed throughout history according to the needs and discretion of the authorities of the Dubrovnik Republic. In the 18th century there were eleven administrative units: eight districts and three captaincies. The island of Mljet was joined to the Dubrovnik commune in 1410 and was ruled by a rector who resided in a village of Babino Polje. Among other things, the Rector served as a judge and, like the role of other rectors and captains who ruled locally, he was not empowered to pass sentences for the most serious crimes committed in the territory under his supervision.