conservator

One who conserves, preserves or protects something.

2014, Paul Salopek, Blessed. Cursed. Claimed., National Geographic (December 2014)https://web.archive.org/web/20150212214621/http://ngm.nationalgeographic.com/2014/12/pilgrim-roads/salopek-text Chlouveraki, a tenacious archaeological conservator, has salvaged antiquities all over the Middle East.

the great Creator and Conservator of the world

A person appointed by a court to manage the affairs of another; similar to a guardian but with some powers of a trustee.

The lords of the secret council were likewise made conservators of the peace of the two kingdoms.

The Governor [of Missouri] is […] the conservator of the peace

An officer in charge of preserving the public peace, such as a justice or sheriff.

A judge delegated by the pope to defend certain privileged classes of persons from manifest or notorious injury or violence, without recourse to a judicial process.

A professional who works on the conservation and restoration of objects, particularly artistic objects.