It is said that Dana saw the need for a strong protector for all of her children, the Tuatha de Danaan and the fae alike, and created the trolls to that end. Born with the strength of the mountains and the patience of the earth itself, the safety and continuation of all the fae falls to the trolls. This is quite a heavy burden. Whereas the sidhe claim their primacy in society based on their belief in primacy of creation, most trolls allow them this conceit. It is truly a small thing compared to the greater responsibility of the guardianship of the entire fae race, and the sidhe can be... irrational when challenged on this matter. Better to let them believe as they wish, so long as it doesn't interfere with the trolls' larger duty, as entrusted by Dana. Most Danaists are strict adherents to the Code of Dagda.
Though a noble belief system, implementation of the Code varies from one principality to another and often along Seelie and Unseelie lines. The most liberal adherents do their absolute best to see that each and every child of the Dreaming survives. To whit, they will fight unarmed rather than with Cold Iron, and will only enter into combat when any and all other options are exhausted. Note that this protectorate extends to humanity, the source of all dreams. Obviously, not all trolls follow, or even attempt to follow, this interpretation. Indeed almost none do these days, or succeed if they try. Still, heroes are made from the pursuit of impossible goals.
At the other extreme is the belief that only the existence of the race itself, and not individuals, is of paramount importance. Followers of this view have few qualms about thrashing those who need it, whether for personal or political reasons, so long as it does not interfere with the survival of the Fae as a whole. Traditionally an Unseelie perspective, it has grown to wider acceptance in modern times, much to the chagrin of many grumps. Nevertheless, all Danaists will close ranks in the face of sufficient outside threat. In one form or another, Danaism is the most popular of al the troll origin myths.