Toa Hagah was the name given to the six elite Toa whose job it was to safeguard Makuta. Each Toa Hagah wore unique armor which identified him or her as a member of this special group. The six Toa Hagah were Norik, Pouks, Bomonga, Iruini, Kualus, and Gaaki.
The Toa Hagah had been chosen to protect Teridax.
In the tens of thousands of years before the Brotherhood of Makuta rebelled against Mata Nui, they often employed Toa as guards. One such Toa team was the Toa Hagah, led by a brave hero named Norik.
When Spiriah was exiled, his Toa Hagah were transferred to other duties.
The Brotherhood of Makuta chose the members of their Toa Hagah teams from existing Toa teams, and the Toa's masks were presented to them by the members of their former teams as a badge of honor.
All Toa Hagah teams carried weapons like Norik's team: special armor, Rhotuka shields, and spears.
The deputy leader of the Toa Hagah was most likely Bomonga.
The various Toa Hagah teams of the Makuta were not all formed at the same time. It took time to recruit Toa, and some Makuta placed more priority on it than others. If a Makuta's region was not a particularly dangerous one, then there there was not much of a rush to get a security detail. There were probably at least a few Makuta who were initially resistant to the idea of having Toa around all the time.