The Dead Isle...
Not sure if this is the kind of thing you wanted:
The Order of Asarualim is known for bringing peace to the Dead That Can Not Rest. These followers of the Goddess travel the lands where they are needed destroying all undead they find, as well as searching for, and destroying all knowledge of the necromantic arts.
The Order has a church in the Valley of Blessings. Founded by the paladin Asarualim, rumours say the valley is sacred to the Goddess and that here her miracles are revealed and her mysteries abound. Entry is forbidden to all save by invite and the entrances are guarded by knights/priests of the Order. It is the home of the Order, to such an extent that all members are buried within the valley. So firm is this believe, that the bodies of their fallen are brought here at whatever cost so they may rest in the Goddesses embrace.
The truth is somewhat darker.... The paladin Asarualim came to the valley some 150 years ago and found a blight upon the land. A evil force was born to the world in the valley. It is not clear what this being was, but it and its forces were slain in the valley by the paladin and a group of priests. A temple was built upon the barrows in which the creature & its own where buried, as a testament to the power of the Goddess.
But not long after, the truth became apparent. The death of such a great evil had opened a doorway of some kind and all that passed away on the site of its death returned. Exactly one year after the battle, in one night of pure terror, the temple was attacked from within by the risen dead of all that had been buried there. As all seemed lost, Asarualim rallied the priests in prayer. The Goddess blessed them with a rainstorm of Holy Water so fierce the water gathered around the barrows, leaving them raised as 3 small islands in the midst of a lake.
The few priests that survived the initial attack barely escaped when mere hours after the dead were destroyed, they rose again! The curse prevents any true death on the island. Claiming to hear the voice of the Goddess, Asarualim urged the priests to battle their way to the lakes waters. Asarualim urged the priests to swim for their lives but was unable to save himself. Battling the dead to clear a path for the last priests, he fell to the dead.
Once off the islands, they were safe, for although the lake waters were no longer holy water, the dead seemed unable to cross.
The remaining priests went their different ways, except for a small group, who felt the valley must be guarded to prevent the escape of the undead. Who knew if the waters would one day recede? This group stayed and patroled the edge of the waters. Thus the order was founded.
The order had since grown in size and guards the valley in case the Blessed Waters ever lose their hold on the dead on the Isles. They also study the undead, as well as the curse upon the land, hoping to break it one day. Initiates come here to train to fight undead, but are also taught about the mystery. Part of the reason thet order fights the undead in other places is to study other events where the undead are found, hoping for clues on how to end the curse.
The party has been recruited after helping a priest of the order put down an infestation of undead and now go to the valley to learn the mysteries of the order, as well as to be trained.