Sidau was a village in Bajor's Hedrikspool Province. For centuries the Sirahna of the village would use the paghvaram, an Orb fragment, to conjur a being known as the Dal'Rok. The Dal'Rok would attack the village and the Sirah would make the villagers work to together to force it away, bringing them closer together. (DS9 episode: "The Storyteller", DS9 - Worlds of Star Trek: Deep Space Nine novel: Bajor: Fragments and Omens)
In 2369, Faren Kag sent a distress call to Deep Space 9, telling them the village was in danger of destruction. Miles O'Brien and Julian Bashir travlled to Sidau, where they discovered the present Sirah was dying and O'Brien was named as his successor. Ke Hovath had been the Sirah's apprentice for several years, but the Sirah did not believe he was ready.
The Sirah died soon after and the Dal'Rok appeared during the night. O'Brien was unable to inspire the villagers enough and Ke stepped in, inspiring them to drive it away, becoming their new Sirah. (DS9 episode: "The Storyteller")
Ke remained Sirah for the next seven years, although during this time he spent time away from the village, becoming interested in the combining both religion and science. During this time, he wrote Speculations on the Architecture of the Celestial Temple, which drew the attention of Iliana Ghemor. In late 2376, Ghemor went to the village with several mercenaries, kidnapping Ke and his wife Iniri. Before the left, they destroyed the village with a triceron explosive and killed the Sidau inhabitants. (DS9 - Worlds of Star Trek: Deep Space Nine novel: Bajor: Fragments and Omens)
In the mirror universe, Ke Hovath was a professor at the Sidau College of Physics before he was recruited to serve in the Klingon-Cardassian Alliance's Research and Development Branch. (DS9 novel: The Soul Key)