Lortheim is a priest of Talos.
He is a priest in the the Temple of Talos in Windhelm. He works there along with his wife, Jora.
If he is killed, his wife Jora may send two hired thugs after the perpetrator.
In The Elder Scrolls V: Dawnguard, he may be questioned during Gunmar's hunting missions to find information about a master vampire.