The Last Lamp is what is left of the Aureum in the Blood Mountains after a century of Chimean occupation: the holdouts who would not scatter into the surface towns the way most surviving Aureum bloodlines did. They are not a nation and do not claim to be one. They are a few hundred fighters, runners, and glass-tenders organized around a single asset, the sealed distribution hall called Candelum, where the only working Aureum light in the range still lies in the glass. Everything the Last Lamp is follows from that fact. They formed to hold the hall, they fight to keep the way to it open, and the day the reserve runs dry is the day they stop being a resistance and become refugees.
The name is older than the fight. Aureum priests were glass-tenders, and the lamp was always the small unit of the work, the share of light a single tender kept moving down a single chain. When the great vaults went dark a century ago, the phrase curdled into something grimmer. There is one lamp left now, and the people guarding it took the description for a name. Orenna, who holds the office of Tender of Candelum, leads them by the same logic the old order ran on: she controls the basin where the day's light is drawn, so she controls the resistance. See her entry for how she spends it.
What the Last Lamp will not say out loud to outsiders is that it is losing two ways at once. The Chimean Second Legion holds the surface and the mines above them, and the Bloodlings hold the deep below them and have started taking Aureum tunnel-runners as readily as Chimean officers. Caught between an occupier and a predator, Orenna has opened a quiet line to the Chimean commander Toben Ashling against the Bloodlings, a truce of pure convenience that most of her own fighters do not know exists and would call treason if they did.
A measure is a day. A day is a runner who comes home, a basin that does not crack, a child who reads by it instead of by nothing. We do not spend a measure on glory. Glory does not refill the glass. — the ration-line litany of the Tenders
The live argument inside the Last Lamp is about what the light is for. Orenna rations it to keep her people alive one more season, and one more after that, on the theory that survival buys time and time is the only thing that might change their odds. The fighting wing reads the same finite reserve and reaches the opposite conclusion: if the light is going to run out anyway, better to pour it into one real blow against the occupation while there is still enough to matter, rather than meter it out until the day it is simply gone and they have won nothing. Both sides know the reserve is finite. Neither can prove how many seasons are left, because the one person who knows the true figure is lying about it to both of them.