Liam Trollbane

Liam Trollbane was the father of Thoras Trollbane, and grandfather of Galen Trollbane and Danath Trollbane.

In the RPG
Prince Liam, grandfather of Galen Trollbane, was so impressed with his servant Yernim Weltom's ingenuity in hiding the castle's artifacts that he appointed him Caretaker of Artifacts with a staff of two, and commanded the young servant to come up with a better plan to protect the artifacts. When nobles of Lordaeron, Khaz Modan and Azeroth would visit Prince Liam, he would proudly tell the story of how Yernim had protected the family heirlooms while the guard was away. With Prince Liam's approval, Yernim Weltom instructed the nobles to send five trusted servants to him for training. Thus the continent wide training of the Caretakers began.

Speculation
Outside of the Ultimate Visual Guide books, Liam isn't mentioned in any other canon sources, but it is likely that he was king of the Stromgarde kingdom and was later succeeded by his son, Thoras.