early modern political alliance

generate a one-sentence description for a given conceptual class.
# Response Format
Return only the sentence: "Description: [one-sentence description of the conceptional class]"

Class: early modern political alliance

An early modern political alliance is a formal or informal agreement between states, dynasties, or political entities from roughly the 15th to 18th centuries to cooperate for mutual security, territorial, economic, or dynastic advantage within a shifting balance-of-power system.