Grand Prince Stavian I of Taldor during the Grand Campaign targeted the religion of Sarenrae, as one aspect of Qadiran society. This easy target helped him to unite his nation against the enemy. In 4528 AR, he made the worshiping of Sarenrae illegal in Taldor and propagandized the Cult of the Dawnflower as treasonous spies. The Taldan society turned against Sarenrae's followers in Taldor and, in a matter of months, all of her temples and places of worship were destroyed and the Dawnflower's clerics and followers were murdered or expelled. This event is known as the Great Purge.
In part, the Great Purge was sparked due to a Sarenite soothsayer claiming that one of six children of Grand Prince Micheaux the Magnificent (which included Stavian I) was a bastard. Upon taking the crown in 4526 AR, Stavian I believed that the infighting with his siblings was a direct result of this prophesy. Declaring the oracle a traitor and his faith, by extension, also treacherous, the Grand Purge began.
The Great Purge was formerly known as the Great Burning of Witches. This become something of a misnomer as fewer than a hundred Sarenite 'witches' were burned in total.
For additional resources, see the Meta page.