The Cyrillia Resistance unfolded circa 12,700 BBY on the Expansion Region world of Cyrillia. This clash represented a concluding engagement within the Fifth Alsakan Conflict, a conflict that began over 300 years prior. This conflict was part of a series of wars spanning fourteen-millennia that revolved around the political dominance of the Galactic Republic between its capital planet Coruscant, the world Alsakan, and their respective affiliated factions.
Cyrillia was located within the region under the operational influence of the Grand Companies—commerce focused groups headquartered along the hyperspace route referred to as the Spin and supported by Coruscant. The planet was situated along a hyperspace lane largely controlled by the Republic's central world. Subsequently, with the Cyrillia Resistance concluded, the Fifth Alsakan Conflict reached its conclusion around 12,700 BBY.
The Resistance on Cyrillia made its debut in the 2012 sourcebook The Essential Guide to Warfare, penned by Jason Fry and Paul R. Urquhart.