Ages of Doubt

The Ages of Doubt were eras in Covenant history where the effects of internal or external conflicts are dealt with. The last Age of Doubt, the 23rd, succeeded the 39th Age of Conflict, when the Unggoy Rebellion destabilized the Covenant, and lasted until the discovery of the Reclaimers (Humanity) and the deposition and replacement of the Hierarchs. This age was succeeded by the Ninth Age of Reclamation in 2525.

Eighteenth Age of Doubt
During the Eighteenth Age of Doubt, the Ruma-pattern light carrier was introduced into active service with the Covenant fleet.

Twenty-Third Age of Doubt (2462–2525)
The Twenty-Third Age of Doubt followed the Thirty-Ninth Age of Conflict in 2462, in which the Unggoy Rebellion threatened the stability of the Covenant. This age was followed by the Ninth Age of Reclamation in 2525.

The Rasus-pattern interdictor was first produced during the Twenty-Third Age of Doubt, with a single ship-of-the-line commissioned—Heaven's Brilliant Bier.

Progression of the Ages
During the Progression of the Ages, an appropriate dialogue is as followed:

Leader, or Chieftain: Doubt.

Congregation, or Pack: ''Sixth! Faith and patience!''

In the ritual, the Ages of Doubt are represented by an opal stone.

Trivia
In Halo Wars, when playing as the Covenant, players can upgrade their Temple by researching the Age of Doubt, improving all Covenant technology by 1. Advancing to the Age of Doubt also gives Covenant players the ability to make Type-30 Locusts, Vampires, and many other types of units.