The Indefatigable class was a class of battlecruisers used by the Solarian League Navy.
By 1920 PD, the Indefatigables began to be replaced by the newer Nevada class in Solarian services.
In 1921 PD, fourteen Flight VII units were illegally sold by Technodyne Industries to the Republic of Monica. Another ten older units were gifted by the Mesan government (controlled by the Mesan Alignment) to the People's Navy in Exile. (SI1, SI2)
- Flights V and VI were equipped with the older SL-11-b missile launcher, with a 45-second launch cycle due to breaking down feed queues.
- Flight VII was equipped with the SL-13 missile launcher with a 35-second cycle.
In 1921 PD, units of the class in both Solarian service and service with the People's Navy in Exile used the Aegis counter missile system. (SI2)
In 1921 PD, the units illegally sold into Monican service underwent minor refits of their impeller nodes and sensors to change their emissions signatures.