The Constellation-class multi-mission guided-missile frigates of the United States Navy are based on the European multipurpose frigates (FREMM), already in service with the French and Italian navies. Constellation follows the modular but problematic littoral combat ships of the Freedom and Independence classes. The U.S. Navy announced the FFG(X) frigate project in the United States Department of Defense's Request For Information (RFI) in July 2017.

The FREMM, which stands for "European multi-purpose frigate", is a Franco-Italian family of multi-purpose frigates designed by Naval Group and Fincantieri. In France, this surface combatant is known as the "Aquitaine class", while in Italy it is known as the "Bergamini class". The lead ship of the class, Aquitaine, was commissioned in November 2012 by the French Navy. Italy has ordered six general purpose and four anti-submarine variants. France, on the other hand, has ordered six anti-submarine variants and two air-defense ones.