Dunedin had a freedom of the city charter with the 4th Otago and Southland Regiment, and in 2012 they amalgamated with the 2nd Canterbury Battalion to form the 2/4 Royal New Zealand Infantry Regiment.
Yesterday's ceremony recognised the amalgamation with the signing of the freedom of the city charter under the regiment's new name.
Mr Cull said in medieval times, freedom of the city was an honour granted only to troops who had earned the trust of the local populace, either through valiant action or simply by being a familiar presence.
``While it is my hope that you will never march in anything but peace, we are fiercely proud to have you as our guardians, and in doing so, we reaffirm the privilege and honour of the freedom of our city of Dunedin.''