After the Alliance to Restore the Republic evacuated the Great Temple on Yavin 4 six months after the Battle of Yavin, High Command, in search of a suitable site to permanently relocate to, established itself within the catacombs of the planet Thila, already an established Rebel base.
The newly formed Rogue Group, under the command of Luke Skywalker, permanently assigned to the High Command group, likewise transferred with High Command to the Thila base. Renegade Flight, under the leadership of Commander Arhul Narra, were similarly assigned to Thila.
High Command only operated out of Thila for a period of months before being forced to evacuate with the threat of its secrecy potentially compromised. Rogue Group performed admirably during several skirmishes during the Thila campaign, assisting High Command in their evacuation efforts, proving their effectiveness. When Imperial forces descended on the Thila outpost, they were ambushed by previously placed explosives.
After Skywalker recommended the remote ice world of Hoth as a possible relocation site, High Command agreed to set up operations there. When the newly constructed Echo Base was completed in 1 ABY, High Command moved there under the command of General Carlist Rieekan.