The Horadrim were a group of ancient magi tasked by Tyrael with capturing the three Prime Evils during the Dark Exile. They eventually captured all three brothers, but left with no task at hand and the threat of imminent danger gone, the order slowly dissolved.
The last living member of the order was Deckard Cain.
The history of the Horadrim begin with the Dark Exile, an event during which the four Lesser Evils banished the three Prime Evils to Sanctuary. For decades the Three ravaged Sanctuary in secret and unbeknownst to the High Heavens. Thus it was that when Tyrael first discovered was transpiring in the lands of Kehjistan he dared not inform any other Council members for fear that it would lead to Sanctuary's destruction. Thus he instead tasked men with eliminating this grave threat.
The first members of the Horadrim came from the remains of the mage clans that had survived the Mage Clan Wars, and were few in number. Tyrael chose seven, though each such mage likely had several retainers, apprentices and other followers with them. The seven were given three soulstones by Tyrael within which they could trap the Prime Evils.
The Hunt for the Three was thus carried out by these Horadric mages, and upon capturing the last Prime Evil Diablo in present day Khanduras, the order was ordered by Tyrael to continue to guard his soulstone lest Diablo somehow break free in the future. The Horadrim thus build a monastery over the site and changed from a wandering band of warrior mages to lorekeepers and guardians. Eventually however the order began to fade, and the purpose and origin of their monastery was lost. Much later it would become the center of the town of Tristram.
- Cain, Deckard., Book of Cain, page 87.
- Cain, Deckard., Book of Cain, page 88.
- Cain, Deckard., Book of Cain, page 92-94.