The Master Builder seemed to have asserted that a new grand strategy (and a new weapon, as well?) made old-fashioned warriors and armies and fleets unnecessary. Shortly thereafter, the Didact and all his fellow Prometheans were removed from the Council. I presumed this was when the Didact was forced into exile and entered the Cryptum. From that time until now, over a thousand years, Warrior-Servants had been increasingly marginalized, their rates reassessed, their forces and fleets and armies disbanded.

Halo: Cryptum Ch 29

	The Master Builder brilliantly chipped away at the Didact’s remaining base of support. The political war between Builders and Warrior-Servants came to a head. Warrior-Servants were reduced as a rate. Many moved to the Builder rate, taking on the role of Builder Security. The insult was obvious—but at least they survived, found prosperity, and became of value to the new regime.

Halo: Silentium Ch 3