I suspect you are thinking of the Geneva Convention Relative to the Protection of Civilian Persons in Time of War, 12 August 1949. This is also referred to as the 4th Geneva Convention. By "take ownership of civilian life", I assume you are talking of setting up occupation governments, rather than simply the rules about killing civilians, which are covered elsewhere in the Conventions. Part III, starting with Article 27, gives very clear guidelines for how civil society must be dealt with by occupiers. Of most importance is Article 27, which states that "Protected persons are entitled, in all circumstances, to respect for their persons, their honor, their family rights, their religious convictions and practices, and their manners and customs..." Section II of this convention governs the protection of aliens present in occupied territories, and Section III governs the protection of citizens of the occupied territory. Perhaps the most important Article with regards to citizens of the occupied territory is Article 47, which states inter alia "Protected persons...shall not be deprived, in any case or in any manner whatsoever, of the benefits of the present convention by any change introduced, as the result of the occupation of a territory, into the institutions or government of the said territory, nor by any agreement concluded between the authorities of the occupied territory and the Occupying power, nor by any annexation by the latter of the whole or part of the occupied territory". Article 49 governs mass deportations or exile, and precludes the occupying power from bringing its own population into the occupied territory. Other Articles govern protection of workers, Children, destruction of property, Hygiene and Public Health, etc. Article 64 governs the penal laws of the occupied territory, and essentially states that the occupying power may not change these laws from the previous controlling party except in specific instances of need.There is also lots of legal protection written in. Similar protections were written into the "Convention respecting the laws and customs of war on Land" (4th Hague Convention), The Hague, 18 October 1907, but these were mostly strengthened by the 1949 rules. If this does not address your original question, please try to restate it in more detail, and I will attempt to respond. References: "The Geneva Conventions of August 12, 1949" -- International Committee of the Red Cross 1989, and "International Law Concerning the Conduct of Hostilities/Collection of Hague Conventions and Some Other Treaties", International Committee of the Red Cross. 1989.