Initially established as a field hospital in the low Balinok Mountains west of Lake Baratok, the Abbey of Brilliant Worship was founded by Alizandra Markovia at the will of Thestus, the "Morninglord". She began to spread her gospel to the forest-folk who previously prayed to the Ladies Three, teaching them that they were not gods, merely powerful Archfey with a deep connection to the land. Even when only partially-constructed, the Abbey was a sanctuary against the mountain winters, and many former "savages" began to settle below its platau.
As the community grew, attacks from forest-folk Barbarians were prominent, and often resulted in death among the populace. Additionally, the warlord Strahd von Zarovich was taking more territory in his family's name, which threatened the sanctity of the Abbey. To protect her growing flock, Alizandra ordered that defensive walls be built around the community below. Now a small fort underneath the abbey, the village gained the name Zachodgrad, or "Westfort", and became a bastion against the gathering forces of the night after the Wedding That Never Was.
After the Sunless March of Saint Markovia, Zachodgrad fell to a siege at Strahd's behest. The remaining militia fled up the switchback to the Abbey, since christened the Abbey of Saint Markovia, and attempted to hold out against the Strahd's forces alongside the clergy. Lacking supply lines, the Abbey fell, its once-high walls buckling under the slow siege tactics of Strahd's forces. The fort was renamed to "Krezk" and it's new burgomaster, Ladislau Krezkov, was not a follower of the Morninglord. Eventually, the church fell into disuse, only occasionally visited by inquisitive children or wandering passers by.
The Abbey was unoccupied for three hundred years, until a Deva was summoned to reconsecrate the once-great church. The Angel named himself The Abbot and set to rebuild the structure, but found that the land had long ago been poisoned by Strahd. At the Abbey's gates, Strahd battled The Abbot, disguised as a nobleman named Vasili von Holtz. He took the deva to the Amber Temple, where his memories were altered and his personality was changed. Ever since, The Abbey has been a housing ground for experiments on dozens of Mongrelfolk from the Belview family, at the behest of Iaseka Belview. Their howls and yips kept away the townsfolk, who were afraid to engage their guardians at the abbey's gate.