Which title refers to the action of leading a rebellion against authority?

The action of leading a rebellion against authority is best captured by the term "insurrection." An insurrection refers specifically to an uprising or revolt against an established authority, often characterized by organized resistance or rebellion. This term is commonly associated with political and social movements where groups of people actively challenge their ruling government or regime.

In contrast, options like "mutiny" typically refer to a rebellion specifically within military ranks, where soldiers or sailors rise against their commanding officers. "Regency" denotes a period of rule by a regent, often during the absence or incapacity of a monarch, and does not pertain to rebellion. "Fiefdom" refers to a domain or estate granted to a vassal by a lord in exchange for service and loyalty, which does not imply an act of rebellion against authority. Therefore, insurrection accurately encompasses the broader act of challenging and rebelling against established power.