The Osean navy acquired 36 Cavalierclass destroyers in the 1970s during an escalation of the Cold War after détente had essentially died out. The ships were to be part of President Hubert's 700-ship navy, although the next administration cut procurement back from the initially planned 52. The surplus vessels were sold to the FCU, the only nation willing to purchase such large and costly destroyers.
Cavaliers are particularly large for destroyers, and their massive hull design was reused for the Excalibur class cruiser and proposed as small STOVL carriers. Modernized with new systems, rolling airframe missile CIWS, and Tomahawk missiles, the vessels stayed in service with both operators into the 2010s, but their lack of phased array Aegis radar made them dated once Yuktobania stole Aegis technology from Belka's Totten class derivatives. Cavaliers were phased out of service in favor of Flight IIA Tottens.