Night's Black Agents: Dracula Dossier
A Castellan was a governor or captain of the castle and its surrounding area. Sometimes known as a constable or a governor. After the fall of the Western Roman Empire, many tribes migrated into Western Europe, causing strife and war. The answer to recurrent invasion was to create fortified areas which evolved into castles. Some leaders gained control of several areas, each with a castle. The problem arose when a leader could only be in one place at a time and thus had to entrust the certain vassals with making decisions in their absence and running the day to do affairs of the castle. The Castellan was, in effect, a lord without noble heritage.
There is a story of The Castellan of Elorrio that seems to have heavy research and shows signs of recent handling (likely irresponsibly). As this story goes, the Castellan, Hugo Fernandez, aided by the brothers at the Abbey of San Pedro, nearby, saw to the needs of the rural area. However, there were strange rumors that Hugo may have been involved in brutal attacks on his servants and subjects, and was quick to anger. The Benedictine monks at the Abbey of San Pedro, according to the author (a priest attached to the Castle of Elorrio) attempted to counsel the Castellan but he often rejected their advice.
One fateful morning, well before dawn, the Castellan was on a hunting trip in the forest surrounding the castle. The author describes that some kind of creature attacked the hunting party, based on the evidence, and the entire party was slaughtered, except for Hugo Fernandez, whose body was never recovered but his horse was located nearby, unharmed. The new Castellan took a far more benign and kind approach to his charges and peasants, however, a rift occurred between he and the monks of San Pedro and he informed them that their counsel would no longer be required.
The author goes on to reference strange disappearances that were heavily documented in the area for years that followed, especially visitors to the area, typically as they were leaving. Curiously, those that disappeared tended to be on the younger side, most often (but not always) individuals between the ages of 8 and 20.
Rumors began to arise that Hugo Fernandez (or his ghost) was haunting the area, turning to cannibalism. Despite numerous search efforts by the locals, no trace was ever found of those that disappeared, or that of Hugo Fernandez. Today the incident remains a mystery even though there are reports of disappearances from time to time, but nowhere near the numbers that happened in the 12th century.