[1] The term also applied as the rank of the field officer that was in charge of a captaincy's territorial militia, called ordenanças in Portuguese, a military unit which existed from the 16th to the 19th centuries.
Due to the impossibility of exercising direct control and sovereignty over overseas territories, the captain-major was the channel by which the monarch could delegate his powers, with certain restrictions, under the responsibility of persons in whom he confided.
The donatário could administer, on behalf of the Sovereign, the lands to which he was assigned, with all the regalia, rights and obligations, with the exception of certain limits, including military authority over soldiers and detachments of the crown, or the administration of justice.
[2] Economically, they had the exclusive authority to mill, bake bread and sell salt, in addition to their entitlement to receive rent paid to the King for lands, fees and due taxes.
[2] Most donatary titles were hereditary, with a few exceptions mentioned in the Salic laws (Portuguese: leis Sálicas) of the time, which regulated all aspects of life, including crime, taxation, indemnity, and female inheritance;[2] captains-major were less restricted to these conditions.