From Halopedia, the Halo wiki
The year 2200 BCE is a year in the 2200s BCE in the 22nd century BCE.
- The year 2200 BCE saw a major turning point in the history of the San'Shyuum (Prophets). After centuries of unity the San'Shyuum become divided into two groups, the Stoics who believe that Forerunner relics were sacred and not to be altered, and the Reformists who wish to more closely examine the artifacts and use them for their own purposes. This fundamental disagreement sparks the War of Wills.
- Halo Encyclopedia (2009 edition), page 114