When Graham was in Kolyma, Hagatha gave Caldaur orders from the Father to kill him. Fortunately for the count, it wasn't long before Graham found his way into Castle Caldaur in search of the Death Gem. Caldaur cornered the king there, and nearly killed him. However, Graham mentioned that Lavidia was dying of an illness. Realizing that Lavidia's death would leave Anastasia unprotected and unaware of the danger of the Brotherhood, he rushed off to turn them both into vampires.
When he and Lavidia returned, as bats, they found Graham climbing down the wall of the castle. Together, they knocked him off the wall and brought him back inside. There, Caldaur insisted that he go on an errand -- to retrieve a sapphire tiara he wished to give to his wife. When Graham returned with the tiara and with news of Llowh'wof's death, Caldaur gave Graham the Death Gem and let him go. He also ended his ties to the Black Cloak Society, determined to spend time with his newly reunited family and restoring the realm he would once again rule.
Appearing only in the AGDI remake King's Quest II: Romancing the Stones, Caldaur was inspired by Count Dracula in the original King's Quest II: Romancing the Throne. The name Caldaur is an anagram of Dracula. His appearance was based on King Ludwig II of Bavaria, featured in Gabriel Knight: The Beast Within.