For centuries, the Alfama Mountains had been the territory of the direct Blood Clan. They thrived here, fed, slept, and from time to time descended to the human world to plunder, capturing blood fodder and sacrifices for their Longevity Blood Ceremony. They were the ancestral homeland of the entire northern branch of the Blood Clan in the empire.
In the entirety of Shire County, or rather all the cities along the Alfama Mountains, the direct Blood Clan had no natural predators, and there were few supernatural forces that could contain them. Hence, these vampires could be called the dominators of the Alfama Mountains. The influence they exerted could easily control half of the underworld in Shire County, like the territory of Count Baine.
Not to mention the lair of these direct Blood Clan members.